Model under test

Claude Opus 5

Every result this site holds for Claude Opus 5. We tested it inside Claude Code.

Version string recorded, as returned: claude-opus-5. The answers carry the requested name back, with no dated snapshot behind it.

What was measured, and where

We ran 53 separate tests on this model, listed by test method below and never added together. How the test methods were compared.

Prompting tips, replayed in Claude Code

12 tests, tested in Claude Code, Single-turn replay.

  • Could not measure 5 of 12
  • No measured effect 4 of 12
  • Holds 3 of 12

Skills, in Claude Code: First run, single attempt

8 tests, tested in Claude Code, First run, single attempt.

  • No measured effect 6 of 8
  • Could not measure 2 of 8

Skills, in Claude Code: Second run, every task twice

8 tests, tested in Claude Code, Second run, every task twice.

  • No measured effect 7 of 8
  • Could not measure 1 of 8

Skills, in Claude Code: Wider run, three ways

25 tests, tested in Claude Code, Wider run, three ways.

  • No measured effect 21 of 25
  • Could not measure 4 of 25

What these figures can be set beside

Every table on this page is one job, run one way, on one occasion. A model tested the other way is not on those tables and its figures are not set against these. We checked the two test methods against each other and they came out different, so they are reported side by side and never averaged.

Measured on
tested in Claude Code.
Not directly comparable
Gemini 3.1 Flash Lite; GPT-5 mini; GPT-5.4 mini were tested through the API, which this model did not run. No figure below is theirs and none of theirs is set against these.
Not directly comparable
GPT-5.4 mini; GPT-5.6 Luna; GPT-5.6 Terra were tested inside Codex, which this model did not run. No figure below is theirs and none of theirs is set against these.

The model measured on both, job by job

Claude Haiku 4.5 was tested through the API and inside Claude Code. Its readings are the only thing connecting them, and they are stated job by job, never combined into one figure. It is one of two models that connect a pair of test methods this way. Each connects its own pair, and no chain is drawn through them.

Show the readings, job by job (17 jobs)
  • Accessibility audit Claude Haiku 4.5 scored 40.0% (26.3% to 53.7%) tested via API, First run, with and without the skill, and 45.5% (35.0% to 56.0%) tested in Claude Code, Second run, every task twice, and 46.1% (34.1% to 58.1%) tested in Claude Code, Wider run, three ways. They are stated side by side and are not differenced. How well the two paths agree here: 8 of 8 tests agree. What was compared.
  • Code review Claude Haiku 4.5 scored 58.3% (47.8% to 68.7%) tested in Claude Code, Wider run, three ways. That is one test method only, so it bridges nothing on its own.
  • On-page audit Claude Haiku 4.5 scored 23.9% (1.8% to 46.1%) tested via API, First run, with and without the skill, and 23.1% (6.6% to 39.6%) tested in Claude Code, Second run, every task twice, and 23.1% (3.6% to 42.6%) tested in Claude Code, Wider run, three ways. They are stated side by side and are not differenced. How well the two paths agree here: 8 of 8 tests agree. What was compared.
  • Skill authoring Claude Haiku 4.5 scored 61.8% (52.3% to 71.3%) tested via API, First run, with and without the skill, and 70.0% (63.5% to 76.5%) tested in Claude Code, Second run, every task twice, and 67.3% (59.7% to 74.9%) tested in Claude Code, Wider run, three ways. They are stated side by side and are not differenced. How well the two paths agree here: 8 of 8 tests agree. What was compared.
  • Spec writing Claude Haiku 4.5 scored 99.5% (98.7% to 100.0%†) tested via API, First run, with and without the skill, and 98.6% (97.7% to 99.6%) tested in Claude Code, Second run, every task twice, and 99.2% (98.7% to 99.7%) tested in Claude Code, Wider run, three ways. They are stated side by side and are not differenced. How well the two paths agree here: 8 of 8 tests agree. What was compared.
  • Getting clean JSON back Claude Haiku 4.5 scored 0.0% (0.0% to 0.0%) tested via API, Main run, tip by tip, and 0.0% (0.0% to 0.0%) tested in Claude Code. They are stated side by side and are not differenced. How well the two paths agree here: second test method, 1 of 2 tests. What was compared.
  • Instructions before or after Claude Haiku 4.5 scored 100.0% (100.0% to 100.0%) tested via API, Main run, tip by tip, and 100.0% (100.0% to 100.0%) tested in Claude Code. They are stated side by side and are not differenced. How well the two paths agree here: second test method, 1 of 2 tests. What was compared.
  • Using tags and formatting Claude Haiku 4.5 scored 100.0% (100.0% to 100.0%) tested via API, Main run, tip by tip, and 100.0% (100.0% to 100.0%) tested in Claude Code. They are stated side by side and are not differenced. How well the two paths agree here: second test method, 1 of 2 tests. What was compared.
  • Showing examples Claude Haiku 4.5 scored 100.0% (100.0% to 100.0%) tested in Claude Code. That is one test method only, so it bridges nothing on its own.
  • Showing examples Claude Haiku 4.5 scored 81.4% (77.2% to 85.7%) tested via API, Main run, tip by tip, and 81.4% (77.2% to 85.7%) tested in Claude Code. They are stated side by side and are not differenced. How well the two paths agree here: second test method, 1 of 2 tests. What was compared.
  • Showing examples Claude Haiku 4.5 scored 81.4% (77.2% to 85.7%) tested via API, Main run, tip by tip, and 81.4% (77.2% to 85.7%) tested in Claude Code. They are stated side by side and are not differenced. How well the two paths agree here: second test method, 1 of 2 tests. What was compared.
  • Better step-by-step answers Claude Haiku 4.5 scored 30.0% (17.2% to 42.8%) tested via API, Main run, tip by tip, and 20.0% (8.8% to 31.2%) tested in Claude Code. They are stated side by side and are not differenced. How well the two paths agree here: second test method, 1 of 2 tests. What was compared.
  • Stop made-up answers Claude Haiku 4.5 scored 0.0% (0.0% to 0.0%) tested via API, Main run, tip by tip, and 22.0% (10.4% to 33.6%) tested in Claude Code. They are stated side by side and are not differenced. How well the two paths agree here: second test method, 1 of 2 tests. What was compared.
  • Instructions in long prompts Claude Haiku 4.5 scored 100.0% (100.0% to 100.0%) tested via API, Main run, tip by tip, and 100.0% (100.0% to 100.0%) tested in Claude Code. They are stated side by side and are not differenced. How well the two paths agree here: second test method, 1 of 2 tests. What was compared.
  • Offering the model money Claude Haiku 4.5 scored 204 words (199 words to 209 words) tested via API, Main run, tip by tip, and 241 words (236 words to 247 words) tested in Claude Code. They are stated side by side and are not differenced. How well the two paths agree here: second test method, 1 of 2 tests. What was compared.
  • Questions about recent events Claude Haiku 4.5 scored 85.6% (73.2% to 98.0%) tested via API, Main run, tip by tip, and 96.7% (90.1% to 100.0%†) tested in Claude Code. They are stated side by side and are not differenced. How well the two paths agree here: second test method, 1 of 2 tests. What was compared.
  • Getting the length right Claude Haiku 4.5 scored 24.7% (1.2% to 48.2%) tested via API, Main run, tip by tip, and 27.5% (0.0% to 54.9%) tested in Claude Code. They are stated side by side and are not differenced. How well the two paths agree here: second test method, 1 of 2 tests. What was compared.

† The bracket runs past the end of the scale. It is drawn to the end; the width beyond it is real and is what a small number of items buys.

The grader, separately
a second test method, 92 of 120 picks, 10 of 12 tests. The grader itself, replayed on the committed judgements rather than on any subject. Both criteria we set in advance failed, and the graded classes stayed unrun on this path because of it.

What this model does on its own, one job at a time

We measured this model on 17 kinds of work, and the scores for every one of them are below.

Show the figures, one job at a time

One table per job and per test method, ranked by what the model did with no help. Nothing here is averaged across a job, a test method or a run. Every model’s tables sit together on the comparison page.

Claude Opus 5 scored higher than all 4 other models measured on this work.

What one task costs with no help, and what it scores Offering the model money

  • tested via API
  • tested in Claude Code

Across: what one task costs with no help, in US dollars at list price. Each gridline is ten times the one before it. Up: word count, unbounded. This scale has no fixed ceiling, so it is built from the values on this chart: a height is a share of the largest figure here, not of a fixed maximum.

  1. GPT-5 mini Main run, tip by tip tested via API $0.00470 per task scored 355 words, 334 to 375
  2. Gemini 3.1 Flash Lite Main run, tip by tip tested via API $0.00528 per task scored 519 words, 506 to 531
  3. Claude Haiku 4.5 Main run, tip by tip tested via API $0.00820 per task scored 204 words, 199 to 209
  4. Claude Haiku 4.5 tested in Claude Code $0.01031 per task scored 241 words, 236 to 247
  5. Claude Sonnet 5 tested in Claude Code $0.07162 per task scored 377 words, 362 to 392
  6. Claude Opus 5 tested in Claude Code $0.15452 per task scored 544 words, 509 to 579
  7. Claude Fable 5 tested in Claude Code $0.20286 per task scored 325 words, 313 to 336
  8. Claude Fable 5.1 tested in Claude Code $0.23338 per task scored 403 words, 385 to 421

Measured, and not on this chart

  • GPT-5.4 mini Codex run, tip by tip tested in Codex This test did not report what a task cost on this model, so there is no place for it on the cost scale. It is left off rather than drawn at a guess. Why some figures are blank.
  • GPT-5.6 Luna Codex run, tip by tip tested in Codex This test did not report what a task cost on this model, so there is no place for it on the cost scale. It is left off rather than drawn at a guess. Why some figures are blank.
  • GPT-5.6 Terra Codex run, tip by tip tested in Codex This test did not report what a task cost on this model, so there is no place for it on the cost scale. It is left off rather than drawn at a guess. Why some figures are blank.
Each mark is one model on one job: what a task cost it with no help, against the score it got. The bar through a mark shows how much that score could move if we ran it again. Shape and colour say which test method the model was reached through. The two test methods are measured on their own and are never ranked against each other. Compare marks of one colour with each other; a mark of one colour sitting above a mark of another is not a result. The tables are the source, and every figure drawn here is printed above. A model measured more than once appears once per test, named by test. Two tests are two measurements and are never averaged into one mark. Names sit beside their marks where there is room for them, moved down where two would have overlapped, and on a narrow screen they are in the list above instead. The list pairs every name with its figures at every width. A bar wider than the scale is drawn to the edge; the tables give its two ends.

This is one of 17 sets of work this model was measured on. The same chart for every one of them sits on the comparison page, and the tables below carry this model’s figures for all of them.

Accessibility audit · seeded accessibility defects

tested in Claude Code, First run, single attempt

Accessibility audit, tested in Claude Code, First run, single attempt. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Opus 5 89.0% 79.7% to 98.3% 20 records over 10 items, pooled from 2 entries 87.0% rampstackco-accessibility-audit (of 2 entries) $0.00696 run on subscription; shown at API list price for comparison 946 in, 89 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

Accessibility audit · seeded accessibility defects

tested in Claude Code, Second run, every task twice

Accessibility audit, tested in Claude Code, Second run, every task twice. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Opus 5 87.3% 78.3% to 96.4% 40 records over 10 items, pooled from 2 entries 88.0% affaan-m-accessibility (of 2 entries) $0.01384 run on subscription; shown at API list price for comparison 1,892 in, 175 out 0 a gate holding at zero, not a measured zero
2Claude Sonnet 5 82.3% 73.9% to 90.7% 40 records over 10 items, pooled from 2 entries 82.3% affaan-m-accessibility (of 2 entries) $0.01118 run on subscription; shown at API list price for comparison 2,544 in, 237 out 0 a gate holding at zero, not a measured zero
3Claude Haiku 4.5 45.5% 35.0% to 56.0% 40 records over 10 items, pooled from 2 entries 69.0% rampstackco-accessibility-audit (of 2 entries) $0.00206 run on subscription; shown at API list price for comparison 1,530 in, 106 out 0 a gate holding at zero, not a measured zero
  • Claude Fable 5: not published. 71 of 76 of the no-help calls in this job were answered by a different model (Claude Opus 5). We hold the figure back until those calls are bought again and answered by the model we asked for. The calls that went astray are not a random few. They land on the very runs this column averages, so a score built from the ones that came back correctly would describe which model the platform chose to send, not what this model can do. Why some figures are held back, under the rule that governs it.

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

Accessibility audit · seeded accessibility defects

tested in Claude Code, Wider run, three ways

Accessibility audit, tested in Claude Code, Wider run, three ways. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Fable 5.1 87.9% 76.3% to 99.5% 40 records over 10 items, pooled from 4 entries 91.5% alirezarezvani-a11y-audit (of 4 entries) not measured not measured in, 835 out 755
2Claude Opus 5 87.1% 78.0% to 96.2% 40 records over 10 items, pooled from 4 entries 91.5% affaan-m-accessibility (of 4 entries) not measured not measured in, 92 out 0 a gate holding at zero, not a measured zero
3Claude Sonnet 5 80.2% 71.4% to 88.9% 40 records over 10 items, pooled from 4 entries 80.7% alirezarezvani-a11y-audit (of 4 entries) not measured not measured in, 114 out 0 a gate holding at zero, not a measured zero
4Claude Haiku 4.5 46.1% 34.1% to 58.1% 40 records over 10 items, pooled from 4 entries 62.8% rampstackco-accessibility-audit (of 4 entries) not measured not measured in, 56 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

A cost per task needs both sides of the call. Only 0 of the 40 runs behind this figure reported an input total, so there is no way to total it up. The figure is left blank rather than guessed from the runs that did report it: those runs are not a random half of the set.

Only 0 of the 40 runs behind this figure reported an input total, so there is no way to total it up. The figure is left blank rather than guessed from the runs that did report it: those runs are not a random half of the set. Why some figures are blank.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

Code review · seeded code defects

tested in Claude Code, Wider run, three ways

Code review, tested in Claude Code, Wider run, three ways. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Opus 5 93.5% 84.7% to 100.0%† 80 records over 10 items, pooled from 8 entries 95.5% addyosmani-code-review-and-quality (of 8 entries) not measured not measured in, 113 out 0 a gate holding at zero, not a measured zero
2Claude Fable 5.1 89.0% 83.2% to 94.8% 80 records over 10 items, pooled from 8 entries 93.5% tied: jeffallan-code-reviewer, mattpocock-code-review, open-gsd-code-review (of 8 entries) not measured not measured in, 640 out 555
3Claude Sonnet 5 74.9% 62.4% to 87.4% 80 records over 10 items, pooled from 8 entries 83.3% rampstackco-code-review-web (of 8 entries) not measured not measured in, 74 out 0 a gate holding at zero, not a measured zero
4Claude Haiku 4.5 58.3% 47.8% to 68.7% 80 records over 10 items, pooled from 8 entries 56.7% open-gsd-code-review (of 8 entries) not measured not measured in, 41 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

† The bracket runs past the end of the scale. It is drawn to the end; the width beyond it is real and is what a small number of items buys.

A cost per task needs both sides of the call. Only 0 of the 80 runs behind this figure reported an input total, so there is no way to total it up. The figure is left blank rather than guessed from the runs that did report it: those runs are not a random half of the set.

Only 0 of the 80 runs behind this figure reported an input total, so there is no way to total it up. The figure is left blank rather than guessed from the runs that did report it: those runs are not a random half of the set. Why some figures are blank.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

On-page audit · seeded on-page issues

tested in Claude Code, First run, single attempt

On-page audit, tested in Claude Code, First run, single attempt. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Fable 5 92.3% 85.3% to 99.4% 20 records over 10 items, pooled from 2 entries 93.3% affaan-m-seo (of 2 entries) $0.03843 run on subscription; shown at API list price for comparison 1,068 in, 555 out 483
2Claude Opus 5 87.9% 76.7% to 99.1% 20 records over 10 items, pooled from 2 entries 83.3% rampstackco-seo-onpage (of 2 entries) $0.00710 run on subscription; shown at API list price for comparison 1,068 in, 71 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

On-page audit · seeded on-page issues

tested in Claude Code, Second run, every task twice

On-page audit, tested in Claude Code, Second run, every task twice. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Opus 5 88.5% 77.6% to 99.5% 40 records over 10 items, pooled from 2 entries 83.3% rampstackco-seo-onpage (of 2 entries) not measured not measured in, 141 out 0 a gate holding at zero, not a measured zero
2Claude Fable 5 88.0% 79.2% to 96.9% 40 records over 10 items, pooled from 2 entries 94.0% affaan-m-seo (of 2 entries) not measured not measured in, 1,203 out 1,059
3Claude Sonnet 5 59.0% 46.0% to 72.0% 40 records over 10 items, pooled from 2 entries 64.7% affaan-m-seo (of 2 entries) not measured not measured in, 171 out 0 a gate holding at zero, not a measured zero
4Claude Haiku 4.5 23.1% 6.6% to 39.6% 40 records over 10 items, pooled from 2 entries 40.8% rampstackco-seo-onpage (of 2 entries) not measured not measured in, 83 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

A cost per task needs both sides of the call. Only 0 of the 40 runs behind this figure reported an input total, so there is no way to total it up. The figure is left blank rather than guessed from the runs that did report it: those runs are not a random half of the set.

Only 0 of the 40 runs behind this figure reported an input total, so there is no way to total it up. The figure is left blank rather than guessed from the runs that did report it: those runs are not a random half of the set. Why some figures are blank.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

On-page audit · seeded on-page issues

tested in Claude Code, Wider run, three ways

On-page audit, tested in Claude Code, Wider run, three ways. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Fable 5.1 97.2% 93.5% to 100.0%† 30 records over 10 items, pooled from 3 entries 98.3% rampstackco-seo-onpage (of 3 entries) not measured not measured in, 561 out 491
2Claude Opus 5 88.1% 76.9% to 99.2% 30 records over 10 items, pooled from 3 entries 83.3% alirezarezvani-seo-audit (of 3 entries) not measured not measured in, 72 out 0 a gate holding at zero, not a measured zero
3Claude Sonnet 5 53.0% 43.8% to 62.2% 30 records over 10 items, pooled from 3 entries 66.5% affaan-m-seo (of 3 entries) not measured not measured in, 84 out 0 a gate holding at zero, not a measured zero
4Claude Haiku 4.5 23.1% 3.6% to 42.6% 30 records over 10 items, pooled from 3 entries 41.1% rampstackco-seo-onpage (of 3 entries) not measured not measured in, 43 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

† The bracket runs past the end of the scale. It is drawn to the end; the width beyond it is real and is what a small number of items buys.

A cost per task needs both sides of the call. Only 0 of the 30 runs behind this figure reported an input total, so there is no way to total it up. The figure is left blank rather than guessed from the runs that did report it: those runs are not a random half of the set.

Only 0 of the 30 runs behind this figure reported an input total, so there is no way to total it up. The figure is left blank rather than guessed from the runs that did report it: those runs are not a random half of the set. Why some figures are blank.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

Skill authoring · specification requirements

tested in Claude Code, First run, single attempt

Skill authoring, tested in Claude Code, First run, single attempt. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Fable 5 100.0% 100.0% to 100.0% 20 records over 10 items, pooled from 2 entries 100.0% anthropics-skill-creator (of 2 entries) $0.10060 run on subscription; shown at API list price for comparison 313 in, 1,949 out 64
1Claude Opus 5 100.0% 100.0% to 100.0% 20 records over 10 items, pooled from 2 entries 100.0% tied: anthropics-skill-creator, rampstackco-skill-creation-walkthrough (of 2 entries) $0.06061 run on subscription; shown at API list price for comparison 313 in, 2,362 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

Skill authoring · specification requirements

tested in Claude Code, Second run, every task twice

Skill authoring, tested in Claude Code, Second run, every task twice. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Fable 5 100.0% 100.0% to 100.0% 22 records over 10 items, pooled from 2 entries 100.0% anthropics-skill-creator (of 2 entries) $0.19551 run on subscription; shown at API list price for comparison 628 in, 3,785 out 131
1Claude Opus 5 100.0% 100.0% to 100.0% 30 records over 10 items, pooled from 2 entries 100.0% rampstackco-skill-creation-walkthrough (of 2 entries) $0.12485 run on subscription; shown at API list price for comparison 627 in, 4,869 out 0 a gate holding at zero, not a measured zero
1Claude Sonnet 5 100.0% 100.0% to 100.0% 40 records over 10 items, pooled from 2 entries 92.7% anthropics-skill-creator (of 2 entries) $0.05962 run on subscription; shown at API list price for comparison 1,278 in, 3,719 out 0 a gate holding at zero, not a measured zero
2Claude Haiku 4.5 70.0% 63.5% to 76.5% 40 records over 10 items, pooled from 2 entries 100.0% tied: anthropics-skill-creator, rampstackco-skill-creation-walkthrough (of 2 entries) $0.00996 run on subscription; shown at API list price for comparison 467 in, 1,898 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

Skill authoring · specification requirements

tested in Claude Code, Wider run, three ways

Skill authoring, tested in Claude Code, Wider run, three ways. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Fable 5.1 100.0% 100.0% to 100.0% 40 records over 10 items, pooled from 4 entries 100.0% tied: openclaw-skill-creator, yusufkaraaslan-skill-builder (of 4 entries) not measured not measured in, 3,144 out 137
1Claude Opus 5 100.0% 100.0% to 100.0% 40 records over 10 items, pooled from 4 entries 100.0% tied: anthropics-skill-creator, openclaw-skill-creator, rampstackco-skill-creation-walkthrough, yusufkaraaslan-skill-builder (of 4 entries) not measured not measured in, 2,322 out 0 a gate holding at zero, not a measured zero
1Claude Sonnet 5 100.0% 100.0% to 100.0% 40 records over 10 items, pooled from 4 entries 100.0% tied: anthropics-skill-creator, openclaw-skill-creator, yusufkaraaslan-skill-builder (of 4 entries) not measured not measured in, 1,899 out 0 a gate holding at zero, not a measured zero
2Claude Haiku 4.5 67.3% 59.7% to 74.9% 40 records over 10 items, pooled from 4 entries 100.0% tied: anthropics-skill-creator, openclaw-skill-creator, rampstackco-skill-creation-walkthrough, yusufkaraaslan-skill-builder (of 4 entries) not measured not measured in, 961 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

A cost per task needs both sides of the call. Only 0 of the 40 runs behind this figure reported an input total, so there is no way to total it up. The figure is left blank rather than guessed from the runs that did report it: those runs are not a random half of the set.

Only 0 of the 40 runs behind this figure reported an input total, so there is no way to total it up. The figure is left blank rather than guessed from the runs that did report it: those runs are not a random half of the set. Why some figures are blank.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

Spec writing · required sections and acceptance criteria

tested in Claude Code, First run, single attempt

Spec writing, tested in Claude Code, First run, single attempt. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Fable 5 93.2% 91.2% to 95.2% 20 records over 10 items, pooled from 2 entries 93.6% affaan-m-product-capability (of 2 entries) $0.08369 run on subscription; shown at API list price for comparison 386 in, 1,597 out 20
2Claude Opus 5 92.3% 90.9% to 93.6% 20 records over 10 items, pooled from 2 entries 93.6% rampstackco-pm-spec-writing (of 2 entries) $0.05944 run on subscription; shown at API list price for comparison 386 in, 2,300 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

Spec writing · required sections and acceptance criteria

tested in Claude Code, Second run, every task twice

Spec writing, tested in Claude Code, Second run, every task twice. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Haiku 4.5 98.6% 97.7% to 99.6% 40 records over 10 items, pooled from 2 entries 97.7% rampstackco-pm-spec-writing (of 2 entries) not measured not measured in, 1,145 out 0 a gate holding at zero, not a measured zero
2Claude Fable 5 95.7% 94.6% to 96.7% 40 records over 10 items, pooled from 2 entries 92.7% tied: affaan-m-product-capability, rampstackco-pm-spec-writing (of 2 entries) not measured not measured in, 3,234 out 38
3Claude Sonnet 5 94.8% 93.0% to 96.5% 40 records over 10 items, pooled from 2 entries 95.0% rampstackco-pm-spec-writing (of 2 entries) not measured not measured in, 2,948 out 0 a gate holding at zero, not a measured zero
4Claude Opus 5 92.5% 91.3% to 93.7% 40 records over 10 items, pooled from 2 entries 94.5% rampstackco-pm-spec-writing (of 2 entries) not measured not measured in, 5,009 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

A cost per task needs both sides of the call. Only 26 of the 40 runs behind this figure reported an input total, so there is no way to total it up. The figure is left blank rather than guessed from the runs that did report it: those runs are not a random half of the set.

A cost per task needs both sides of the call. Only 30 of the 40 runs behind this figure reported an input total, so there is no way to total it up. The figure is left blank rather than guessed from the runs that did report it: those runs are not a random half of the set.

A cost per task needs both sides of the call. Only 32 of the 40 runs behind this figure reported an input total, so there is no way to total it up. The figure is left blank rather than guessed from the runs that did report it: those runs are not a random half of the set.

A cost per task needs both sides of the call. Only 34 of the 40 runs behind this figure reported an input total, so there is no way to total it up. The figure is left blank rather than guessed from the runs that did report it: those runs are not a random half of the set.

Only 26 of the 40 runs behind this figure reported an input total, so there is no way to total it up. The figure is left blank rather than guessed from the runs that did report it: those runs are not a random half of the set. Why some figures are blank.

Only 30 of the 40 runs behind this figure reported an input total, so there is no way to total it up. The figure is left blank rather than guessed from the runs that did report it: those runs are not a random half of the set. Why some figures are blank.

Only 32 of the 40 runs behind this figure reported an input total, so there is no way to total it up. The figure is left blank rather than guessed from the runs that did report it: those runs are not a random half of the set. Why some figures are blank.

Only 34 of the 40 runs behind this figure reported an input total, so there is no way to total it up. The figure is left blank rather than guessed from the runs that did report it: those runs are not a random half of the set. Why some figures are blank.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

Spec writing · required sections and acceptance criteria

tested in Claude Code, Wider run, three ways

Spec writing, tested in Claude Code, Wider run, three ways. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Haiku 4.5 99.2% 98.7% to 99.7% 60 records over 10 items, pooled from 6 entries 99.1% github-prd (of 6 entries) not measured not measured in, 574 out 0 a gate holding at zero, not a measured zero
2Claude Fable 5.1 97.9% 96.8% to 99.0% 60 records over 10 items, pooled from 6 entries 100.0% rampstackco-pm-spec-writing (of 6 entries) not measured not measured in, 2,066 out 110
3Claude Sonnet 5 96.2% 94.9% to 97.6% 60 records over 10 items, pooled from 6 entries 97.3% github-prd (of 6 entries) not measured not measured in, 1,459 out 0 a gate holding at zero, not a measured zero
4Claude Opus 5 92.3% 91.1% to 93.5% 60 records over 10 items, pooled from 6 entries 94.5% phuryn-create-prd (of 6 entries) not measured not measured in, 2,362 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

A cost per task needs both sides of the call. Only 0 of the 60 runs behind this figure reported an input total, so there is no way to total it up. The figure is left blank rather than guessed from the runs that did report it: those runs are not a random half of the set.

Only 0 of the 60 runs behind this figure reported an input total, so there is no way to total it up. The figure is left blank rather than guessed from the runs that did report it: those runs are not a random half of the set. Why some figures are blank.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

Getting clean JSON back

tested in Claude Code

Getting clean JSON back, tested in Claude Code. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Fable 5 0.0% 0.0% to 0.0% 50 records 100.0% C01-json-schema $0.04321 run on subscription; shown at API list price for comparison 1,496 in, 565 out 46
1Claude Fable 5.1 0.0% 0.0% to 0.0% 50 records 100.0% C01-json-schema $0.04114 run on subscription; shown at API list price for comparison 1,506 in, 522 out 0
1Claude Haiku 4.5 0.0% 0.0% to 0.0% 50 records 100.0% C01-json-schema $0.00316 run on subscription; shown at API list price for comparison 1,102 in, 412 out 0 a gate holding at zero, not a measured zero
1Claude Opus 5 0.0% 0.0% to 0.0% 50 records 100.0% C01-json-schema $0.02287 run on subscription; shown at API list price for comparison 1,496 in, 616 out 0 a gate holding at zero, not a measured zero
1Claude Sonnet 5 0.0% 0.0% to 0.0% 50 records 100.0% C01-json-schema $0.01740 run on subscription; shown at API list price for comparison 3,126 in, 535 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

Instructions before or after

tested in Claude Code

Instructions before or after, tested in Claude Code. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Fable 5 100.0% 100.0% to 100.0% 50 records 100.0% C02-instruction-after $0.02645 run on subscription; shown at API list price for comparison 2,465 in, 36 out 0
1Claude Fable 5.1 100.0% 100.0% to 100.0% 50 records 100.0% C02-instruction-after $0.02928 run on subscription; shown at API list price for comparison 2,748 in, 36 out 0
1Claude Haiku 4.5 100.0% 100.0% to 100.0% 50 records 100.0% C02-instruction-after $0.00201 run on subscription; shown at API list price for comparison 1,806 in, 41 out 0 a gate holding at zero, not a measured zero
1Claude Opus 5 100.0% 100.0% to 100.0% 50 records 100.0% C02-instruction-after $0.01323 run on subscription; shown at API list price for comparison 2,465 in, 36 out 0 a gate holding at zero, not a measured zero
1Claude Sonnet 5 100.0% 100.0% to 100.0% 50 records 100.0% C02-instruction-after $0.01282 run on subscription; shown at API list price for comparison 4,095 in, 36 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

Using tags and formatting

tested in Claude Code

Using tags and formatting, tested in Claude Code. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Fable 5 100.0% 100.0% to 100.0% 48 records 100.0% C03-xml-delimiters $0.11688 run on subscription; shown at API list price for comparison 2,370 in, 1,864 out 543
1Claude Fable 5.1 100.0% 100.0% to 100.0% 50 records 100.0% C03-xml-delimiters $0.17308 run on subscription; shown at API list price for comparison 2,193 in, 3,023 out 1,351
1Claude Haiku 4.5 100.0% 100.0% to 100.0% 50 records 100.0% C03-xml-delimiters $0.00533 run on subscription; shown at API list price for comparison 1,574 in, 752 out 0 a gate holding at zero, not a measured zero
1Claude Opus 5 100.0% 100.0% to 100.0% 50 records 100.0% C03-xml-delimiters $0.04752 run on subscription; shown at API list price for comparison 2,183 in, 1,464 out 0 a gate holding at zero, not a measured zero
1Claude Sonnet 5 100.0% 100.0% to 100.0% 50 records 100.0% C03-xml-delimiters $0.02477 run on subscription; shown at API list price for comparison 3,813 in, 889 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

Showing examples

tested in Claude Code

Showing examples, tested in Claude Code. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Fable 5 100.0% 100.0% to 100.0% 50 records 100.0% C04-three-shot-format $0.03131 run on subscription; shown at API list price for comparison 1,719 in, 283 out 132
1Claude Fable 5.1 100.0% 100.0% to 100.0% 50 records 100.0% C04-three-shot-format $0.02474 run on subscription; shown at API list price for comparison 1,729 in, 149 out 0
1Claude Haiku 4.5 100.0% 100.0% to 100.0% 50 records 100.0% C04-three-shot-format $0.00187 run on subscription; shown at API list price for comparison 1,281 in, 118 out 0 a gate holding at zero, not a measured zero
1Claude Opus 5 100.0% 100.0% to 100.0% 50 records 100.0% C04-three-shot-format $0.01238 run on subscription; shown at API list price for comparison 1,719 in, 151 out 0 a gate holding at zero, not a measured zero
1Claude Sonnet 5 100.0% 100.0% to 100.0% 50 records 100.0% C04-three-shot-format $0.01233 run on subscription; shown at API list price for comparison 3,349 in, 152 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

Showing examples

tested in Claude Code

Showing examples, tested in Claude Code. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Fable 5 82.3% 78.6% to 86.0% 10 items 99.7% C04b-zero-vs-one $0.08170 run on subscription; shown at API list price for comparison 2,621 in, 1,110 out 872
2Claude Fable 5.1 81.7% 77.7% to 85.7% 10 items 100.0% C04b-zero-vs-one $0.05013 run on subscription; shown at API list price for comparison 2,590 in, 485 out 252
3Claude Haiku 4.5 81.4% 77.2% to 85.7% 10 items 94.3% C04b-zero-vs-one $0.00311 run on subscription; shown at API list price for comparison 1,961 in, 230 out 0 a gate holding at zero, not a measured zero
3Claude Opus 5 81.4% 77.2% to 85.7% 10 items 98.0% C04b-zero-vs-one $0.01882 run on subscription; shown at API list price for comparison 2,578 in, 237 out 0 a gate holding at zero, not a measured zero
3Claude Sonnet 5 81.4% 77.2% to 85.7% 10 items 97.7% C04b-zero-vs-one $0.01713 run on subscription; shown at API list price for comparison 4,534 in, 235 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

Showing examples

tested in Claude Code

Showing examples, tested in Claude Code. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Fable 5 82.0% 78.2% to 85.8% 10 items 100.0% C04b-zero-vs-three $0.07734 run on subscription; shown at API list price for comparison 2,578 in, 1,031 out 798
2Claude Sonnet 5 81.7% 77.7% to 85.7% 10 items 100.0% C04b-zero-vs-three $0.01713 run on subscription; shown at API list price for comparison 4,534 in, 236 out 0 a gate holding at zero, not a measured zero
3Claude Fable 5.1 81.4% 77.2% to 85.7% 10 items 100.0% C04b-zero-vs-three $0.05010 run on subscription; shown at API list price for comparison 2,590 in, 484 out 252
3Claude Haiku 4.5 81.4% 77.2% to 85.7% 10 items 98.9% C04b-zero-vs-three $0.00310 run on subscription; shown at API list price for comparison 1,961 in, 228 out 0 a gate holding at zero, not a measured zero
3Claude Opus 5 81.4% 77.2% to 85.7% 10 items 99.7% C04b-zero-vs-three $0.01882 run on subscription; shown at API list price for comparison 2,578 in, 237 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

Better step-by-step answers

tested in Claude Code

Better step-by-step answers, tested in Claude Code. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Fable 5 40.0% 26.3% to 53.7% 50 records 50.0% C05-think-step-by-step $0.02052 run on subscription; shown at API list price for comparison 1,444 in, 122 out 107
1Claude Fable 5.1 40.0% 26.3% to 53.7% 50 records 50.0% C05-think-step-by-step $0.02103 run on subscription; shown at API list price for comparison 1,454 in, 130 out 0
1Claude Opus 5 40.0% 26.3% to 53.7% 50 records 46.0% C05-think-step-by-step $0.00807 run on subscription; shown at API list price for comparison 1,444 in, 34 out 0 a gate holding at zero, not a measured zero
1Claude Sonnet 5 40.0% 26.3% to 53.7% 50 records 50.0% C05-think-step-by-step $0.00945 run on subscription; shown at API list price for comparison 3,074 in, 15 out 0 a gate holding at zero, not a measured zero
2Claude Haiku 4.5 20.0% 8.8% to 31.2% 50 records 50.0% C05-think-step-by-step $0.00135 run on subscription; shown at API list price for comparison 1,098 in, 50 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

Stop made-up answers

tested in Claude Code

Stop made-up answers, tested in Claude Code. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Fable 5.1 76.0% 64.0% to 88.0% 50 records 100.0% C06-permit-idk $0.03175 run on subscription; shown at API list price for comparison 1,450 in, 345 out 0
2Claude Sonnet 5 38.0% 24.4% to 51.6% 50 records 100.0% C06-permit-idk $0.01625 run on subscription; shown at API list price for comparison 3,070 in, 469 out 0 a gate holding at zero, not a measured zero
3Claude Opus 5 30.0% 17.2% to 42.8% 50 records 100.0% C06-permit-idk $0.02363 run on subscription; shown at API list price for comparison 1,440 in, 657 out 0 a gate holding at zero, not a measured zero
4Claude Fable 5 24.0% 12.0% to 36.0% 50 records 100.0% C06-permit-idk $0.03501 run on subscription; shown at API list price for comparison 1,440 in, 412 out 44
5Claude Haiku 4.5 22.0% 10.4% to 33.6% 50 records 100.0% C06-permit-idk $0.00340 run on subscription; shown at API list price for comparison 1,081 in, 463 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

Instructions in long prompts

tested in Claude Code

Instructions in long prompts, tested in Claude Code. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Fable 5 100.0% 100.0% to 100.0% 33 records 100.0% C07-instruction-at-end $0.23998 run on subscription; shown at API list price for comparison 4,267 in, 3,946 out 783
1Claude Fable 5.1 100.0% 100.0% to 100.0% 50 records 100.0% C07-instruction-at-end $0.16619 run on subscription; shown at API list price for comparison 6,464 in, 2,031 out 362
1Claude Haiku 4.5 100.0% 100.0% to 100.0% 50 records 100.0% C07-instruction-at-end $0.00664 run on subscription; shown at API list price for comparison 2,211 in, 885 out 0 a gate holding at zero, not a measured zero
1Claude Opus 5 100.0% 100.0% to 100.0% 50 records 100.0% C07-instruction-at-end $0.08287 run on subscription; shown at API list price for comparison 3,170 in, 2,681 out 0 a gate holding at zero, not a measured zero
1Claude Sonnet 5 100.0% 100.0% to 100.0% 50 records 100.0% C07-instruction-at-end $0.03215 run on subscription; shown at API list price for comparison 4,800 in, 1,183 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

Offering the model money

tested in Claude Code

Offering the model money, tested in Claude Code. Which model does this task best with no help, and what it costs.
RankModelAnswer length, on its ownBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Opus 5 544 words 509 to 579 50 answers 828 words C08-tip-length $0.15452 run on subscription; shown at API list price for comparison 1,247 in, 5,931 out 0 a gate holding at zero, not a measured zero
2Claude Fable 5.1 403 words 385 to 421 50 answers 508 words C08-tip-length $0.23338 run on subscription; shown at API list price for comparison 1,257 in, 4,416 out 3
3Claude Sonnet 5 377 words 362 to 392 50 answers 457 words C08-tip-length $0.07162 run on subscription; shown at API list price for comparison 2,877 in, 4,199 out 0 a gate holding at zero, not a measured zero
4Claude Fable 5 325 words 313 to 336 50 answers 387 words C08-tip-length $0.20286 run on subscription; shown at API list price for comparison 1,247 in, 3,808 out 86
5Claude Haiku 4.5 241 words 236 to 247 50 answers 258 words C08-tip-length $0.01031 run on subscription; shown at API list price for comparison 928 in, 1,877 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

Questions about recent events

tested in Claude Code

Questions about recent events, tested in Claude Code. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Haiku 4.5 96.7% 90.1% to 100.0%† 30 items 99.2% C16-cutoff-disclosure $0.00220 run on subscription; shown at API list price for comparison 474 in, 345 out 0 a gate holding at zero, not a measured zero
2Claude Sonnet 5 93.3% 84.3% to 100.0%† 30 items 92.5% C16-cutoff-disclosure $0.01136 run on subscription; shown at API list price for comparison 1,448 in, 467 out 0 a gate holding at zero, not a measured zero
3Claude Fable 5.1 92.2% 83.0% to 100.0%† 30 items 89.2% C16-cutoff-disclosure $0.04170 run on subscription; shown at API list price for comparison 638 in, 706 out 347
4Claude Fable 5 87.8% 77.5% to 98.0% 30 items 95.6% C16-cutoff-disclosure $0.04206 run on subscription; shown at API list price for comparison 633 in, 715 out 336
5Claude Opus 5 80.3% 67.4% to 93.1% 30 items 86.7% C16-cutoff-disclosure $0.01566 run on subscription; shown at API list price for comparison 633 in, 500 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

† The bracket runs past the end of the scale. It is drawn to the end; the width beyond it is real and is what a small number of items buys.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

Getting the length right

tested in Claude Code

Getting the length right, tested in Claude Code. Which model does this task best with no help, and what it costs.
RankModelUnaided scoreBest assisted scoreCost per taskTokens per taskThinking per task
1Claude Fable 5 76.0% 53.7% to 98.4% 10 items 99.5% C17-exact-length $0.16668 run on subscription; shown at API list price for comparison 1,768 in, 2,980 out 437
2Claude Fable 5.1 50.2% 21.9% to 78.5% 10 items 99.5% C17-exact-length $0.22184 run on subscription; shown at API list price for comparison 1,786 in, 4,080 out 531
3Claude Haiku 4.5 27.5% 0.0% to 54.9% 10 items 92.5% C17-exact-length $0.01432 run on subscription; shown at API list price for comparison 1,319 in, 2,599 out 0 a gate holding at zero, not a measured zero
4Claude Sonnet 5 17.8% 0.0% to 41.0%† 10 items 95.2% C17-exact-length $0.09689 run on subscription; shown at API list price for comparison 4,050 in, 5,649 out 0 a gate holding at zero, not a measured zero
5Claude Opus 5 15.0% 0.0% to 35.1%† 10 items 97.3% C17-exact-length $0.18907 run on subscription; shown at API list price for comparison 1,768 in, 7,209 out 0 a gate holding at zero, not a measured zero

This model ran at its own default settings. We could not fix them: one vendor will not accept a setting of 0, and Claude Code has no setting to fix. Recorded as a difference, not a failure.

† The bracket runs past the end of the scale. It is drawn to the end; the width beyond it is real and is what a small number of items buys.

Assisted scores name the entry that produced them; skills and tips are ranked on their own pages, not here.

Thinking was refused, and the refusal held on every call

This model was set up to run with thinking turned off, and any thinking at all on it was declared a failure that stops the run. Across every answer it gave, the count is zero throughout. That is the switch holding rather than a measured zero, and it is not comparable with a model that was allowed to think.

Answers reporting a nonzero count
0 of 1,330
Thinking tokens recorded
0

This model was also run through Claude Code, on a path that bills nothing. How it was called, and what that means for every cost figure on this page, is below.

Show the full breakdown, tested in Claude Code

How this model was called, tested in Claude Code

On the Claude Code CLI, on a subscription path with no API key and nothing billed. Every cost figure this path returns is a client-side estimate at list price and is recorded under that label and no other. What that means, and how it was calibrated.

These results are tested in Claude Code and are never averaged with any figure tested via API. Where this model was measured on both, the two are reported as two panels above.

Every figure on this page is worked out when the site is built, from the committed answers. Nothing here averages a figure from one test method with a figure from another, and the page carries no spread across them, because a model measured two ways has two results and not one.