Anthropic · Benchmarks

Claude Fable 5.1 benchmarks

Claude Fable 5.1 has 6 published scores in this dataset, from a Anthropic release dated 2026-09-01. Its composite index is 91.2, which places it 5th of 22 ranked models. Its strongest area is reasoning (index 96.1) and its weakest is coding (index 84.7). Its best placing is on Humanity's Last Exam, where its 60.9 ranks 2nd of 23 models with a published score.

Closed APIOfficial page

Category profile

Index 0–100: each score relative to the best published score on that test.

ReasoningCodingAgenticKnowledge
Reasoning
96.1#1 of 16 · 2 tests
Coding
84.7#5 of 13 · 2 tests
Agentic
92.91 test · not ranked
Knowledge
—no data

Model facts

Lab
Anthropic
Type
Closed API
Released
2026-09-01
Context
1M
API price / 1M tokens
$10 in · $50 out

Claude Fable 5.1 pricing and open alternatives

Claude Fable 5.1 is only available through Anthropic's API, so it cannot be self-hosted; it costs $10 per million input tokens and $50 per million output tokens.

Open-weight alternatives

The highest-ranked open models, which you can run on your own GPU.

Claude Fable 5.1 speed and pricing

Measured figures link to their source; estimates are labelled.

API output speed
71 tok/sArtificial Analysis median · Artificial Analysis
Time to first token
3.78 sOpenRouter model page provider stats
API price per 1M tokens
$10.00 in · $50.00 outlab list price · Anthropic pricing docs
Compare speed and price across all models

Score by test

Rank is among every model with a published score on that test.

GPQA Diamond93.7%GPQA Diamond; AA independent run (Max, Default Fallback)#4 of 19 · 2.3 behind GPT-6 AstraHumanity's Last Exam60.9%Humanity's Last Exam, no tools; max effort#2 of 23 · 3.5 behind Claude Opus 5.5Humanity's Last Exam (with tools)65.0%Humanity's Last Exam, with tools; max effort (Opus 5.5 system card lists Fable 5.1 at 65.6%)#3 of 17 · 5.0 behind Kimi K3.1 ProSWE-bench Pro81.2%SWE-bench Pro; adaptive thinking max effort; avg of 5 trials#3 of 9 · 8.7 behind Claude Opus 5.5Terminal-Bench 4.055.8%Terminal-Bench 4.0; max effort, Claude Code --bare, 15 trials/task (Mythos 5.1 scored 60.9%)#7 of 16 · 14.8 behind Claude Sonnet 5.5LMArena Text Elo1504LMArena Text, Overall; snapshot Oct 27, 2026; Claude Fable 5.1 (Max); +/-6#3 of 21 · 16 behind Gemini 4 Argon

Nearby in the composite ranking

Models with the closest composite index.

  1. 1Kimi K3.1 Pro94.4
  2. 2Claude Sonnet 5.591.9
  3. 3GPT-6 Astra91.4
  4. 4Claude Fable 5.191.2
  5. 5DeepSeek V4 Pro91.0
  6. 6Kimi K390.6
  7. 7Tencent Hy4 Preview89.9

Head-to-head comparisons

Side-by-side pages built from the tests both models report.

Sources

ModelTestScoreSettingSource
Claude Fable 5.1GPQA Diamond93.7GPQA Diamond; AA independent run (Max, Default Fallback)Artificial Analysis
Claude Fable 5.1Humanity's Last Exam60.9Humanity's Last Exam, no tools; max effortAnthropic Claude Fable 5.1 / Mythos 5.1 System Card (Table 8.1.A)
Claude Fable 5.1Humanity's Last Exam (with tools)65.0Humanity's Last Exam, with tools; max effort (Opus 5.5 system card lists Fable 5.1 at 65.6%)Anthropic Claude Fable 5.1 / Mythos 5.1 System Card (Table 8.1.A)
Claude Fable 5.1SWE-bench Pro81.2SWE-bench Pro; adaptive thinking max effort; avg of 5 trialsAnthropic Claude Fable 5.1 / Mythos 5.1 System Card (Table 8.1.A / sec 8.2)
Claude Fable 5.1Terminal-Bench 4.055.8Terminal-Bench 4.0; max effort, Claude Code --bare, 15 trials/task (Mythos 5.1 scored 60.9%)Anthropic Claude Fable 5.1 / Mythos 5.1 System Card (sec 8.6)
Claude Fable 5.1LMArena Text Elo1504LMArena Text, Overall; snapshot Oct 27, 2026; Claude Fable 5.1 (Max); +/-6LMArena (arena.ai) Text leaderboard

Scores are published results from model cards, lab reports, and public leaderboards, each linked to its source. Settings such as thinking mode or test version differ between sources and are shown next to each score. OpenLLM Buddy catalog models are uncensored fine-tunes; their scores are those of the official base model. Data collected 2026-10-30. How the index works