Claude Fable 5.1 at a glance
Fable 5.1 improves coding and long-running work over Fable 5 at the same $10/$50 list price, while Mythos 5.1 is limited to verified cyber and life-sciences organizations.
Current standing
As of
- Rank
- #9of 43 models
Claude Fable 5.1 (Max) · 49.2 on the Artificial Analysis Intelligence Index v5.0.1 (opens in a new tab)
- Recorded at publication
- 49 (v5.0.1)
as of
- Current leader
- Gemini 4 Carbon (Google) · 60
Computed from our daily snapshot; it changes as new models are measured. Anthropic ships Claude Fable 5.1 and Mythos 5.1
What changed with Claude Fable 5.1
Claude Fable 5.1 is available on the Claude API as claude-fable-5-1 and on AWS, Google Cloud and Microsoft Azure. Anthropic reported 55.8% on Terminal-Bench 4.0, up from 42.0% for Fable 5. Mythos 5.1 is the same model with looser safeguards, offered only through Anthropic's Cyber and Life Sciences Verification Programs to US organizations.
List pricing is $10 input and $50 output per million tokens, with cache reads cut to $0.25. Anthropic estimates typical workloads cost about 25% less than on Fable 5, and up to about 45% less for highly agentic work.
Claude Fable 5.1 benchmarks and pricing
Values are copied from the linked source on the date shown. They are not IA Compa measurements.
- Input price per 1M tokensas of · Source for Input price per 1M tokens: anthropic.com (opens in a new tab)
- $10.00
- Output price per 1M tokensas of · Source for Output price per 1M tokens: anthropic.com (opens in a new tab)
- $50.00
- Context windowas of · Source for Context window: platform.claude.com (opens in a new tab)
- 1M tokens
- Artificial Analysis Intelligence Indexas of · Source for Artificial Analysis Intelligence Index: artificialanalysis.ai (opens in a new tab)
- 49 (v5.0.1)
- Output speedas of · Source for Output speed: artificialanalysis.ai (opens in a new tab)
- 88 tokens/s
How it compares
Other models in the same category that we have covered, using each model's latest recorded value. (Models)
Claude Fable 5.1 reasoning effort
Artificial Analysis tests this model at several reasoning-effort settings. Higher effort usually scores higher but costs more and answers more slowly.
Claude Fable 5.1 by effort level
Higher effort lets the model think longer. Here is what each setting scores, how fast it writes, and what it costs on Artificial Analysis.
| Effort | Intelligence Index | Output speed (tokens per second) | Cost to run the index | Blended price (3:1) (per 1M tokens) | Price in / out (per 1M tokens) | First token |
|---|---|---|---|---|---|---|
| Max (Claude Fable 5.1 (max)) · Best: highest effort with a score, used in the leaderboard | 49 | 88 | $13,327 | $20 | $10 / $50 | 186 s |
| Extra high (Claude Fable 5.1 (xhigh)) | 50 | 86 | $10,097 | $20 | $10 / $50 | 66 s |
| High (Claude Fable 5.1 (high)) | 47 | 87 | $6,618 | $20 | $10 / $50 | 16 s |
| Medium (Claude Fable 5.1 (medium)) | 43 | 86 | $4,897 | $20 | $10 / $50 | 11 s |
| Low (Claude Fable 5.1 (low)) | 39 | 86 | $3,886 | $20 | $10 / $50 | 9.8 s |
Where to compare Claude Fable 5.1
Independent leaderboards and official resources for comparing this model yourself. Rankings change often; each site shows its own current data.
Leaderboards
General leaderboards
Official resources
Why Claude Fable 5.1 matters for businesses
For most business automation, Fable 5.1 is a premium tier. Within weeks, Opus 5.5 scored higher on Anthropic's own coding tests at a lower price, so Fable 5.1 makes most sense where its specific strengths are proven.
Sources for this story
- Introducing Claude Fable 5.1 and Claude Mythos 5.1 (archived September 1, 2026) (opens in a new tab)Official
Anthropic via Internet Archive · web.archive.org
- Introducing Claude Fable 5.1 and Claude Mythos 5.1 (opens in a new tab)Official
Anthropic · anthropic.com
- Claude Platform release notes (opens in a new tab)Official
Anthropic · platform.claude.com
- Claude Fable 5.1 model page (opens in a new tab)Benchmark
Artificial Analysis · artificialanalysis.ai
Last verified: . IA Compa summarizes public announcements for business readers. We are not affiliated with the companies mentioned. Always confirm details, pricing, and availability with the official source.
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