Anthropic·#3 of 351 on the current board
Claude Fable 5.1 is a language model from Anthropic. It ranks #3 of 351 on ModelCap's current board, with an Index score of 85.8, measured on 4 public benchmarks. Its score range of 81.1–90.5 spans positions #1–#10. It is listed at $10.00 per million input tokens and $50.00 per million output tokens across 4 providers. It reads up to 1M tokens of context, with no downloadable weights linked in the current source data.
Figures as of 18 Oct 2026, 00:40 UTC · download the public dataset · methodology
Published Max, X-High, High and other configurations for this model. These are sourced scores, not head-to-head essays.
BES normalizes admitted public benchmark evidence for measured Index rows. Its legacy score and observables prior do not define the public language rank.
These adoption and deployment observations remain context only. They do not change this model's ModelCap Index score or rank.
The bounded 0–100 capability score blends each source’s competitive placement with its published achievement, then combines capability families. Evidence breadth adds a modest uncertainty adjustment; price and popularity are not part of benchmark-led rank.
Not yet published: a pinned repository revision, the architecture and model type, a parameter count, safetensors weight metadata, the base model it derives from, a declared licence, a link to the licence terms, pinned evaluation dataset versions.
A metadata completeness and deployability index—not a safety certification, quality grade, or production-readiness claim.
Market Gravity uses OpenRouter’s full-catalogue popularity order. Sparse Vercel top-ten observations appear only when published and do not affect the score.
OpenRouter weekly popularity across the full model catalogue.
Independent providers versus the model's open or closed cohort, weighted by uptime.
Hugging Face 30-day downloads for open models; neutral for closed models.
Time since first public availability, on a six-month half-life.
anthropic/claude-fable-5.1OpenRouter catalogue or provider-endpoint declaration. Limits can vary by provider and prompt length; a model-wide maximum has not been independently verified. OpenRouter metadata
Models within 3 places of #3 on the ModelCap Index.
Index score within 3 points of, or above, this model's, with a lower listed blended price (3:1 input:output).
The same publisher's other current models with a public Index position.
Claude Fable 5.1 holds ModelCap Index position #3 of 351 ranked language models as of 18 October 2026, with an Index score of 85.8 (interval 81.1–90.5); evidence: measured. The Index combines public benchmark boards with published uncertainty; the methodology page explains the weighting.
Claude Fable 5.1 is listed at $10.00 per 1M input tokens and $50.00 per 1M output tokens as of 18 October 2026 across 4 providers. Prices come from the OpenRouter catalogue and re-observe on every refresh. For 1,000 requests using 2,000 input and 500 output tokens each, the listed rates imply $45.00 total (2M input + 0.5M output). This excludes caching, batch discounts, prompt-length tiers, tool charges and retries; verify the chosen endpoint's rate and limits before budgeting.
Claude Fable 5.1 has a published context window of 1M tokens (1,000,000). The snapshot lists a 128,000 token catalogue-declared route output cap. OpenRouter catalogue or provider-endpoint declaration. Limits can vary by provider and prompt length; a model-wide maximum has not been independently verified. The providers table lists each endpoint's context limit.
No linked weights. No downloadable model weights are linked in the current source data. This does not identify every API or chat product that offers the model.
4 providers serve Claude Fable 5.1 through OpenRouter as of 18 October 2026: Azure, Anthropic, Amazon Bedrock and Google. Each provider's price, context limit, quantization and measured uptime are in the providers table above.
Claude Fable 5.1 has published results on 8 public boards tracked by ModelCap as of 18 October 2026: Arena text 1502 (#6 of 416), Arena coding 1537 (#14 of 411), LMArena Agent 14.0% (#3 of 52), ARC-AGI-2 90.0% (#14 of 261) and AA Intelligence Index 53.4 (#6 of 134) and more. Each board page ranks every tracked model on that benchmark. The ModelCap Index scores the results its methodology admits, with published uncertainty, and shows reference boards without scoring them.
Claude Fable 5.1 ranks #3 (Index 85.8) and Claude Opus 5.5 ranks #2 (Index 87.3) on the ModelCap Index as of 18 October 2026. The head-to-head page lines up their benchmarks, listed prices, context windows and provider counts side by side.
Claude Fable 5.1 first appeared in the catalogue on 1 Sept 2026. It is the current version in its family. Rank and price movements since then are recorded on the site's changes feed.