# Claude Fable 5.1 spotted on DesignArena

Claude Fable 5.1 is a model from Anthropic, released on 1 Sep 2026. First seen 8 Sep 2026. Catalogues list a 1,000,000 tokens context window. 12 evidence links.

- Kind: Sighting
- Developer: Anthropic
- Confidence: Confirmed
- First seen: 2026-09-08T22:06:48.727Z
- Model: [Claude Fable 5.1](https://alexgetman.com/models/anthropic/claude-fable-5-1/)
- Canonical: https://alexgetman.com/signals/2026/09/08/claude-fable-5-1-max-default-fallback/

## Evidence links

- [DesignArena · uicomponent](https://www.designarena.ai/leaderboard?category=uicomponent)
- [DesignArena · website](https://www.designarena.ai/leaderboard?category=website)
- [DesignArena · uicomponent](https://www.designarena.ai/leaderboard/ui-components)
- [DesignArena · website](https://www.designarena.ai/leaderboard/website)
- [models.dev · catalogue](https://models.dev/#claude-fable-5-1)
- [OpenRouter](https://openrouter.ai/anthropic/claude-fable-5.1)
- [OpenCode · discovery](https://opencode.ai/data/anthropic/claude-fable-5-1)
- [Artificial Analysis · benchmarks](https://artificialanalysis.ai/models)
- [Vercel AI Gateway](https://vercel.com/ai-gateway)
- [models.dev · catalogue](https://models.dev/#claude-fable-5.1)
- [Anthropic · model index](https://platform.claude.com/docs/en/models/overview)
- [Arena · leaderboards](https://www.anthropic.com/claude-fable-and-mythos-5-1)