Anthropic · Released Sep 1, 2026
Claude Fable 5.1
Claude Fable 5.1 improves on Claude Fable 5 across the board, with the biggest gains in agentic coding, long-running agentic workflows, and knowledge work: long code refactors, front-end and visual...
- #1ProofBench
- #1OTIS Mock AIME
- Top 3%SciCode
- Top 4%LMCA
- Released
- Sep 1 2026
- Context window
- 1M 128K out
- Input / 1M tokens
- $10.00
- Output / 1M tokens
- $50.00
Where to run it
4 providers compared
All 4 providers charge the same: $10.00 / $50.00 per 1M input / output tokens.
| Provider | Input | Output | Cache read | Context | Max output | Uptime | vs. best |
|---|---|---|---|---|---|---|---|
| Azure | $10.00 | $50.00 | $0.25 | 1M | 128K | 100%24h | Cheapest |
| Anthropic | $10.00 | $50.00 | $0.25 | 1M | 128K | 100%24h | Cheapest |
| Googleglobal | $10.00 | $50.00 | $0.25 | 1M | 128K | 100%24h | Cheapest |
| Amazon Bedrock | $10.00 | $50.00 | $0.25 | 1M | 128K | — | Cheapest |
Value
Price vs. performance
Claude Fable 5.1 Other Anthropic Other labs Value frontier · FrontierSWE vs. input price per 1M tokens (log scale) · Drag to pan, pinch or Ctrl + scroll to zoom, double-click to zoom in.
Benchmarks
25 benchmark scores
| Benchmark | Score | Rank | Leader |
|---|---|---|---|
| FrontierSWESoftware engineering · Ultra-long-horizon engineering tasks with a 20-hour budget each | 56.3% | #4of 19 | GPT-6 Astra65.5% |
| CursorBenchSoftware engineering · Ambiguous multi-file tasks drawn from real Cursor sessions | 51.8% | #4of 16 | Claude Opus 5.557.8% |
| FrontierCodeSoftware engineering · Mergeable fixes for hard open-source issues | 50.9% | #6of 41 | Claude Opus 5.554.6% |
| MirrorCodeSoftware engineering · Reimplement whole programs end-to-end without the source | 73.3% | #2of 9 | Claude Opus 5.577.4% |
| GSOSoftware engineering · Optimize real code to make it significantly faster | 88.2% | #1of 20 | This model |
| SciCodeSoftware engineering · Research-coding problems from the natural sciences | 63.1% | #2of 93 | Claude Opus 5.566.9% |
| WeirdML v3Software engineering · Unfamiliar ML and data tasks with vague goals | 26.0% | #4of 22 | GPT-6 Astra42.2% |
| APEX-AgentsAgents & computer use · Long professional tasks in banking, consulting and law | 68.6% | #4of 51 | Gemini 4 Argon82.4% |
| Remote Labor IndexAgents & computer use · Real paid freelance projects done end-to-end | 17.9% | #3of 13 | Claude Opus 5.521.3% |
| Vending-Bench 2Agents & computer use · Run a simulated vending business for a year (final balance) | $5,422 | #25of 61 | GPT-6 Astra$15,515 |
| GDP.pdfWriting & content · Answer questions about real professional PDFs | 29.6% | #7of 38 | GPT-6.1 Sol35.0% |
| SimpleQA VerifiedWriting & content · Factual accuracy on 1,000 short questions | 70.8% | #6of 66 | Gemini 4 Argon76.0% |
| WebDev ArenaDesign & visual · People vote on which model builds the better website (Elo) | 1758 | #5of 88 | Claude Opus 5.51820 |
| Blueprint-Bench 2Design & visual · Turn apartment photos into 2D floor plans | 41.9% | #4of 32 | Gemini 4 Argon54.4% |
| Furniture AssemblyDesign & visual · Spot mistakes in photos of IKEA builds | 70.0% | #6of 34 | Claude Opus 5.583.3% |
| Humanity's Last ExamReasoning & knowledge · Expert questions across 100+ subjects | 46.5% | #2of 23 | GPT-6 Astra54.8% |
| ARC-AGI-2Reasoning & knowledge · Few-shot abstract reasoning on grid puzzles | 90.0% | #7of 63 | GPT-6 Astra95.0% |
| ARC-AGI-1Reasoning & knowledge · Pattern induction from input–output examples | 97.5% | #8of 63 | Gemini 4 Argon98.5% |
| CritPtReasoning & knowledge · Open-ended, research-level physics problems | 31.1% | #6of 96 | GPT-5.6 Sol32.3% |
| Chess PuzzlesReasoning & knowledge · Find the single best move in 100 new puzzles | 48.0% | #17of 70 | GPT-6 Astra76.0% |
| LMCAReasoning & knowledge · Judge the quality of conceptual arguments like experts | 65.5% | #3of 96 | Claude Sonnet 5.568.3% |
| FrontierMathMaths · Expert-written problems, undergrad to early research (tiers 1–3) | 90.2% | #4of 72 | GPT-6.1 Sol93.7% |
| FrontierMath Tier 4Maths · Exceptionally hard research-level problems | 87.8% | #6of 62 | GPT-6.1 Sol100.0% |
| ProofBenchMaths · Graduate maths proofs verified in Lean 4 | 100.0% | #1of 70 | Claude Sonnet 5.5100.0% |
| OTIS Mock AIMEMaths · Competition-style problems harder than MATH Level 5 | 100.0% | #1of 90 | Gemini 4 Argon100.0% |
Specs
Details
- Model ID
anthropic/claude-fable-5.1- Developer
- Anthropic
- Release date
- Sep 1, 2026 ·
- Context window
- 1,000,000 tokens
- Max output
- 128,000 tokens
- API price
- $10.00 / $50.00 per 1M input / output tokens
- Providers
- 4
- Input types
- text, image, file
- Reasoning
- Yes
- Tool calling
- Yes
- Open weights
- No
- Free tier
- No
Release date, prices and providers from OpenRouter's catalog; buying directly from a provider can cost a little differently. Uptime is the share of OpenRouter requests each provider served over the last day. Benchmark scores are the best result per benchmark from Epoch AI, licensed CC BY 4.0. Rank counts every model tracked here with a score.