Claude Fable 5.1
Anthropic's model for demanding reasoning and long-horizon agentic work; adaptive thinking always on, default effort high. Available via API, GitHub Copilot (admin opt-in) and Kiro limited preview.

Benchmark Results
Score in Elo; the axis starts at 1,200, as Elo has no zero. Higher is better.
Score in Elo; the axis starts at 1,270, as Elo has no zero. Higher is better.
Score in index. Higher is better.
Score in index. Higher is better.
Score in Elo; the axis starts at 1,600, as Elo has no zero. Higher is better.
Score in %. Higher is better.
Score in %. Higher is better.
Score in %. Higher is better.
Score in %. Higher is better.
Score in %. Higher is better.
Score in %. Higher is better.
Score in %. Higher is better.
Score in %. Higher is better.
Score in %. Higher is better.
Where this comes from
Lineage
Claude Fable 5 is the parent (successor)medium confidencenotesWhere this comes from
Identity
Where this comes from
Architecture and Size
- Architecture
- not in the notes Not disclosed
- Total parameters
- – sources
- Active parameters
- –
- Checkpoint parameters
- –
- Context length
- 1,000,000 tokens
- Input
- text, image
- Output
- text
Where this comes from
Openness and Access
- Openness
- proprietary
- Licence
- Proprietary sources
- Access routes
- API
Where this comes from
Deployment
- Runs on
- not in the notes
- Footprint
- Vendor cloud/API only (T1). Max output 128K tokens.
- Runtimes
- not in the notes
Where this comes from
Indonesia
- Indonesian support
- not stated
- Regional languages
- not in the notes
- Jakarta hosting
- unknown
- Languages
- Anthropic docs state all current models support multilingual capabilities; Bahasa Indonesia not verified
Where this comes from
Industry Use Cases
No industry use case links this model.
Links
Anthropicfrontier lab, USA
Claude Fable 5.1Anthropic, multimodal LLM
PT Pertamina Geothermal EnergyIn production, 14 Jul 2026
PT Amman Mineral Nusa Tenggara (AMMAN)In production, 8 Jul 2026
Banner HealthIn production, 11 Jan 2026CommureIn production, 11 Jan 2026+45 moreDeployments of these use cases; none names this model.Organisations 1
Sources
- Models overview platform.claude.com/docs/en/models/overview https://platform.claude.com/docs/en/models/overview
- Best AI models, October 2026: Opus 5.5, GPT-6, Gemini slash-digital.io https://slash-digital.io/en/insights/ai-models-2026/
- LLM Leaderboard - Comparison of AI models from OpenAI, Anthropic, Google, SpaceXAI & others | Artificial Analysis artificialanalysis.ai https://artificialanalysis.ai/leaderboards/models
- Claude Fable 5.1 Benchmarks, Cost and Capabilities | Vals AI vals.ai https://vals.ai/models/anthropic_claude-fable-5-1
- Models overview platform.claude.com/docs/en/about-claude/models/overview https://platform.claude.com/docs/en/about-claude/models/overview
- Supported AI models in GitHub Copilot - GitHub Docs docs.github.com https://docs.github.com/en/copilot/reference/ai-models/supported-models
- Models - Docs - Kiro kiro.dev https://kiro.dev/docs/models/
- HLE Leaderboard: Claude Fable 5.1 Leads at 65% benchlm.ai https://www.benchlm.ai/benchmarks/hle
- Best LLM for Coding (October 2026): SWE-bench & LiveCodeBench Ranked benchlm.ai https://benchlm.ai/coding
- MMMU Leaderboard & Scores , October 2026 benchlm.ai https://www.benchlm.ai/benchmarks/mmmu
To cite this page: Project AURION, AI Use-Cases Research & Innovation, "Claude Fable 5.1", https://aurion.semai.id/models/anthropic-claude-fable-5-1/, records of October 2026.