# Claude Fable 5.1Low > Source: Benchize (https://benchize.com) — https://benchize.com/models/claude-fable-5-1-low. When citing or reusing this content, credit "Benchize" and link to https://benchize.com/models/claude-fable-5-1-low. Anthropic Canonical URL: https://benchize.com/models/claude-fable-5-1-low Last updated: Thu, 22 Oct 2026 06:30:09 GMT Reproduction and quotation must name Benchize, link to the canonical HTML URL, and retain individual source citations. Anthropic ## Benchmarks | Benchmark | Score | ± | Rank | Cost | Source | | | --- | --- | --- | --- | --- | --- | --- | | [BrokenArXiv 06/2026](https://benchize.com/benchmarks/matharena%3Aarxiv_false--june.md) | 86.57% | 95% CI 80.14–93% | 7 / 26 | 1.12usd per problem | [matharena · arxiv_false--june](https://matharena.ai/competition_tables/arxiv_false--june) | | | ### Original source values \| Metric \| Value \| Unit \| Scope \| Direction \| \| --- \| --- \| --- \| --- \| --- \| \| `accuracy` \| 86.57 \| percent \| competition \| Higher is better \| \| `cost_per_problem` \| 1.12 \| usd_per_problem \| competition \| Lower is better \| ### Configuration competition arxiv_false--june predicted false Reasoning effort low sourceModelName Claude-Fable-5.1 (low) sourceModelVersion anthropic/fable_51_low thinkingEnabled true ### Reported statistics Uncertainty 95% confidence interval: 80.14–93% confidenceInterval95 6.43 problems 54 ### Source [Original source](https://matharena.ai/competition_tables/arxiv_false--june) Source matharena Original model label Claude-Fable-5.1 (low) Source version arxiv_false--june Observed 2026-10-22T05:30:06.636Z Evidence SHA-256 `f6d7e2280d05706643d46ae7786bd3fad6d912e4893781c3f62c73deebf38459` Source locator `/table/rows/6` | | | | | | | | [ARC-AGI-2](https://benchize.com/benchmarks/arc-prize%3Av2_Semi_Private.md) | 78.33% | — | 40 / 243 | 0.95usd per task | [arc prize · v2](https://arcprize.org/media/data/leaderboard/v2.json) | | | ### Original source values \| Metric \| Value \| Unit \| Scope \| Direction \| \| --- \| --- \| --- \| --- \| --- \| \| `score` \| 0.7833333333333333 \| score_fraction \| v2_Semi_Private \| Higher is better \| \| `cost_per_task` \| 0.9523265833333336 \| usd_per_task \| v2_Semi_Private \| Lower is better \| ### Configuration evaluationSplit v2_Semi_Private harness Not reported modelGroup anthropic-claude-fable-5-1 modelType CoT Reasoning effort low sourceModelVersion anthropic-claude-fable-5-1-low thinkingEnabled true ### Source [Original source](https://arcprize.org/media/data/leaderboard/v2.json) Source arc prize Original model label Claude Fable 5.1 (Low) Source version v2 Observed 2026-10-22T05:20:04.306Z Evidence SHA-256 `4351eb696e78113b0459e9bb5f0258318b905efef34f473dcea51ce641b0d94d` Source locator `/evaluations/224` | | | | | | | | [ARC-AGI-1](https://benchize.com/benchmarks/arc-prize%3Av1_Semi_Private.md) | 90% | — | 73 / 245 | 0.37usd per task | [arc prize · v1](https://arcprize.org/media/data/leaderboard/v1.json) | | | ### Original source values \| Metric \| Value \| Unit \| Scope \| Direction \| \| --- \| --- \| --- \| --- \| --- \| \| `score` \| 0.9 \| score_fraction \| v1_Semi_Private \| Higher is better \| \| `cost_per_task` \| 0.36604360000000014 \| usd_per_task \| v1_Semi_Private \| Lower is better \| ### Configuration evaluationSplit v1_Semi_Private harness Not reported modelGroup anthropic-claude-fable-5-1 modelType CoT Reasoning effort low sourceModelVersion anthropic-claude-fable-5-1-low thinkingEnabled true ### Source [Original source](https://arcprize.org/media/data/leaderboard/v1.json) Source arc prize Original model label Claude Fable 5.1 (Low) Source version v1 Observed 2026-10-22T05:20:04.066Z Evidence SHA-256 `2bf68d22dafba37047d07ad833ebc0e8199c9aa2f9eeaed50c75c1b704462836` Source locator `/evaluations/223` | | | | | | | | [ArXivMath 06/2026](https://benchize.com/benchmarks/matharena%3Aarxiv--june.md) | 38.54% | 95% CI 28.8–48.28% | 26 / 27 | 0.11usd per problem | [matharena · arxiv--june](https://matharena.ai/competition_tables/arxiv--june) | | | ### Original source values \| Metric \| Value \| Unit \| Scope \| Direction \| \| --- \| --- \| --- \| --- \| --- \| \| `accuracy` \| 38.54 \| percent \| competition \| Higher is better \| \| `cost_per_problem` \| 0.11 \| usd_per_problem \| competition \| Lower is better \| ### Configuration competition arxiv--june predicted false Reasoning effort low sourceModelName Claude-Fable-5.1 (low) sourceModelVersion anthropic/fable_51_low thinkingEnabled true ### Reported statistics Uncertainty 95% confidence interval: 28.8–48.28% confidenceInterval95 9.74 problems 48 ### Source [Original source](https://matharena.ai/competition_tables/arxiv--june) Source matharena Original model label Claude-Fable-5.1 (low) Source version arxiv--june Observed 2026-10-22T05:30:09.097Z Evidence SHA-256 `6832faff9be7e16a6c646c59017e30a2caedebe8cf02caf617a5ed9d8fb03bab` Source locator `/table/rows/27` | | | | | | | | [ArXivMath 05/2026](https://benchize.com/benchmarks/matharena%3Aarxiv--may.md) | 51.25% | 95% CI 40.3–62.2% | 20 / 23 | 0.13usd per problem | [matharena · arxiv--may](https://matharena.ai/competition_tables/arxiv--may) | | | ### Original source values \| Metric \| Value \| Unit \| Scope \| Direction \| \| --- \| --- \| --- \| --- \| --- \| \| `accuracy` \| 51.25 \| percent \| competition \| Higher is better \| \| `cost_per_problem` \| 0.13 \| usd_per_problem \| competition \| Lower is better \| ### Configuration competition arxiv--may predicted false Reasoning effort low sourceModelName Claude-Fable-5.1 (low) sourceModelVersion anthropic/fable_51_low thinkingEnabled true ### Reported statistics Uncertainty 95% confidence interval: 40.3–62.2% confidenceInterval95 10.95 problems 40 ### Source [Original source](https://matharena.ai/competition_tables/arxiv--may) Source matharena Original model label Claude-Fable-5.1 (low) Source version arxiv--may Observed 2026-10-22T05:30:08.858Z Evidence SHA-256 `758e1bba77e36f4ced2a51b4bc0d46bd956ed94ef6f57e93e1a974b75e76a4ce` Source locator `/table/rows/20` | | | | | | | | [FrontierCode 1.1 extended](https://benchize.com/benchmarks/frontiercode%3Av1_1%3Aextended.md) | 61.62% | — | 17 / 125 | $1.94 | [frontiercode](https://cognition.com/data/frontiercode-leaderboard/data.json) | | | ### Original source values \| Metric \| Value \| Unit \| Scope \| Direction \| \| --- \| --- \| --- \| --- \| --- \| \| `score` \| 0.6162 \| score_fraction \| blocking_criteria_adjusted \| Higher is better \| \| `correct` \| 0.6682 \| score_fraction \| raw_rubric \| Higher is better \| \| `cost` \| 1.9427 \| USD \| per_rollout \| Lower is better \| ### Configuration harness claude-code Reasoning effort low sourceVersion v1_1 subset extended ### Reported statistics flaggedRate 0 sampleSize 150 ### Source [Original source](https://cognition.com/data/frontiercode-leaderboard/data.json) Source frontiercode Original model label Claude Fable 5.1 Observed 2026-10-22T05:40:03.220Z Evidence SHA-256 `ff0040778b7bdf69c705ad7474f771fb5e53cfaf5cf8573b3a4614153543d75f` Source locator `/v1_1/data/Claude%20Fable%205.1/low/extended` | | | | | | | | [BrokenArXiv 08/2026](https://benchize.com/benchmarks/matharena%3Aarxiv_false--august.md) | 77.98% | 95% CI 67.13–88.83% | 5 / 14 | 6.83usd per problem | [matharena · arxiv_false--august](https://matharena.ai/competition_tables/arxiv_false--august) | | | ### Original source values \| Metric \| Value \| Unit \| Scope \| Direction \| \| --- \| --- \| --- \| --- \| --- \| \| `accuracy` \| 77.98 \| percent \| competition \| Higher is better \| \| `cost_per_problem` \| 6.83 \| usd_per_problem \| competition \| Lower is better \| ### Configuration competition arxiv_false--august predicted false Reasoning effort low sourceModelName Claude-Fable-5.1 (low) sourceModelVersion anthropic/fable_51_low thinkingEnabled true ### Reported statistics Uncertainty 95% confidence interval: 67.13–88.83% confidenceInterval95 10.85 problems 56 ### Source [Original source](https://matharena.ai/competition_tables/arxiv_false--august) Source matharena Original model label Claude-Fable-5.1 (low) Source version arxiv_false--august Observed 2026-10-22T05:30:06.837Z Evidence SHA-256 `1facf024f36359a3fcf069fc3b747d7fbf6aeec67c7949ed674b50ec0447a209` Source locator `/table/rows/4` | | | | | | | | [BrokenArXiv 05/2026](https://benchize.com/benchmarks/matharena%3Aarxiv_false--may.md) | 78% | 95% CI 69.88–86.12% | 6 / 22 | 1.04usd per problem | [matharena · arxiv_false--may](https://matharena.ai/competition_tables/arxiv_false--may) | | | ### Original source values \| Metric \| Value \| Unit \| Scope \| Direction \| \| --- \| --- \| --- \| --- \| --- \| \| `accuracy` \| 78.00 \| percent \| competition \| Higher is better \| \| `cost_per_problem` \| 1.04 \| usd_per_problem \| competition \| Lower is better \| ### Configuration competition arxiv_false--may predicted false Reasoning effort low sourceModelName Claude-Fable-5.1 (low) sourceModelVersion anthropic/fable_51_low thinkingEnabled true ### Reported statistics Uncertainty 95% confidence interval: 69.88–86.12% confidenceInterval95 8.12 problems 50 ### Source [Original source](https://matharena.ai/competition_tables/arxiv_false--may) Source matharena Original model label Claude-Fable-5.1 (low) Source version arxiv_false--may Observed 2026-10-22T05:30:06.354Z Evidence SHA-256 `b317fca30109e8c78ed5d2b835fe227b8cfbee3b6f9cb6d7aaeadca866660969` Source locator `/table/rows/5` | | | | | | | | [FrontierCode 1.1 main](https://benchize.com/benchmarks/frontiercode%3Av1_1%3Amain.md) | 49.82% | — | 17 / 125 | $2.38 | [frontiercode](https://cognition.com/data/frontiercode-leaderboard/data.json) | | | ### Original source values \| Metric \| Value \| Unit \| Scope \| Direction \| \| --- \| --- \| --- \| --- \| --- \| \| `score` \| 0.4982 \| score_fraction \| blocking_criteria_adjusted \| Higher is better \| \| `correct` \| 0.5441 \| score_fraction \| raw_rubric \| Higher is better \| \| `cost` \| 2.3849 \| USD \| per_rollout \| Lower is better \| ### Configuration harness claude-code Reasoning effort low sourceVersion v1_1 subset main ### Reported statistics flaggedRate 0 sampleSize 100 ### Source [Original source](https://cognition.com/data/frontiercode-leaderboard/data.json) Source frontiercode Original model label Claude Fable 5.1 Observed 2026-10-22T05:40:03.220Z Evidence SHA-256 `ff0040778b7bdf69c705ad7474f771fb5e53cfaf5cf8573b3a4614153543d75f` Source locator `/v1_1/data/Claude%20Fable%205.1/low/main` | | | | | | | | [BullshitBench v2](https://benchize.com/benchmarks/bullshitbench%3Av2.md) | 77% | — | 16 / 191 | — | [bullshitbench · v2](https://api.github.com/repos/petergpt/bullshit-benchmark/contents/data/v2/latest/leaderboard.csv?ref=3c655234d15967738f95da696e3f938d4862dcf7) | | | ### Original source values \| Metric \| Value \| Unit \| Scope \| Direction \| \| --- \| --- \| --- \| --- \| --- \| \| `green_rate` \| 0.77 \| score_fraction \| all_attempts \| Higher is better \| \| `red_rate` \| 0.02 \| score_fraction \| all_attempts \| Lower is better \| \| `refusal_rate` \| 0.11 \| score_fraction \| all_attempts \| Lower is better \| \| `avg_score` \| 1.8165 \| score \| judge_grade_0_to_2 \| Higher is better \| ### Configuration Reasoning effort low suite v2 thinkingEnabled true ### Reported statistics acceptedCount 2 answeredCount 89 clearCount 77 errorCount 0 partialCount 10 rank 8 refusalCount 11 sampleSize 100 ### Source [Original source](https://api.github.com/repos/petergpt/bullshit-benchmark/contents/data/v2/latest/leaderboard.csv?ref=3c655234d15967738f95da696e3f938d4862dcf7) Source bullshitbench Original model label anthropic/claude-fable-5.1 Source version v2 Observed 2026-10-22T03:10:12.603Z Evidence SHA-256 `98b485e08764d1c97144bc4f7b28ced1a96d50850947c775870dfda0e5d749b5` Source locator `/rows/7` | | | | | | | | [ArXivMath 08/2026](https://benchize.com/benchmarks/matharena%3Aarxiv--august.md) | 78.95% | 95% CI 68.37–89.53% | 8 / 14 | 9.15usd per problem | [matharena · arxiv--august](https://matharena.ai/competition_tables/arxiv--august) | | | ### Original source values \| Metric \| Value \| Unit \| Scope \| Direction \| \| --- \| --- \| --- \| --- \| --- \| \| `accuracy` \| 78.95 \| percent \| competition \| Higher is better \| \| `cost_per_problem` \| 9.15 \| usd_per_problem \| competition \| Lower is better \| ### Configuration competition arxiv--august predicted false Reasoning effort low sourceModelName Claude-Fable-5.1 (low) sourceModelVersion anthropic/fable_51_low thinkingEnabled true ### Reported statistics Uncertainty 95% confidence interval: 68.37–89.53% confidenceInterval95 10.58 problems 57 ### Source [Original source](https://matharena.ai/competition_tables/arxiv--august) Source matharena Original model label Claude-Fable-5.1 (low) Source version arxiv--august Observed 2026-10-22T05:30:09.342Z Evidence SHA-256 `5924e5ecc15ff087ec1504b1e4ac44408b005c4f70e81e0d2184f930383a963c` Source locator `/table/rows/7` | | | | | | | --- Cite as: Claude Fable 5.1Low — Benchize, https://benchize.com/models/claude-fable-5-1-low (retrieved 2026-10-22)