Claude Fable 5.1
Summary
Claude Fable 5.1 is a proprietary language model from Anthropic, released on 1 Sept 2026. It accepts text, images and PDFs and generates text, with a 1M-token context window and up to 128K output tokens per response. As of 4 Oct 2026, the lowest listed API price is $10 per million input tokens and $50 per million output tokens (Claude API), across 7 providers we track.
Claude model for demanding reasoning and long-horizon agentic work
Last verified 4 Oct 2026. Every figure on this page links to its source.
Specifications
| Developer | Anthropic |
|---|---|
| Release date | 1 Sept 2026 [models.dev] |
| Status | Generally available [models.dev] |
| Weights | Proprietary (API only) [models.dev] |
| Context window | 1M (1,000,000 tokens) [models.dev] |
| Max output | 128K tokens [models.dev] |
| Knowledge cutoff | Jun 2026 [models.dev] |
| Input | Text, images and PDFs [models.dev] |
| Output | Text [models.dev] |
| Reasoning mode | Yes [models.dev] |
| Tool calling | Yes [models.dev] |
| Structured output | Yes [models.dev] |
Claude Fable 5.1 API pricing by provider
USD per million tokens. Sorted by input price.
| Provider | Input | Output | Cached input | Context | Source |
|---|---|---|---|---|---|
| Claude API claude-fable-5-1 | $10 | $50 | $0.25 | 1M | models.dev, 4 Oct 2026 |
| Azure AI Foundry claude-fable-5-1 | $10 | $50 | $0.25 | 1M | models.dev, 4 Oct 2026 |
| Vertex AI (Claude) claude-fable-5-1@default | $10 | $50 | $0.25 | 1M | models.dev, 4 Oct 2026 |
| Amazon Bedrock global.anthropic.claude-fable-5-1 | $10 | $50 | $0.25 | 1M | models.dev, 4 Oct 2026 |
| Amazon Bedrock anthropic.claude-fable-5-1 | $10 | $50 | $0.25 | 1M | models.dev, 4 Oct 2026 |
| Google Vertex AI claude-fable-5-1@default | $10 | $50 | $0.25 | 1M | models.dev, 4 Oct 2026 |
| Vercel AI Gateway anthropic/claude-fable-5.1 | $10 | $50 | $0.25 | 1M | models.dev, 4 Oct 2026 |
| OpenRouter anthropic/claude-fable-5.1 | $10 | $50 | $0.25 | 1M | OpenRouter, 4 Oct 2026 |
| Amazon Bedrock us.anthropic.claude-fable-5-1 | $11 | $55 | $0.28 | 1M | models.dev, 4 Oct 2026 |
Frequently asked questions
What is the context window of Claude Fable 5.1?
Claude Fable 5.1 has a context window of 1,000,000 tokens (1M) and can generate up to 128,000 tokens in a single response, according to models.dev.
How much does the Claude Fable 5.1 API cost?
Through Claude API, Claude Fable 5.1 costs $10 per million input tokens and $50 per million output tokens. Prices last verified 4 Oct 2026.
Is Claude Fable 5.1 open source?
No. Claude Fable 5.1 is a proprietary model; Anthropic has not released its weights. It is available through APIs including Claude API, Azure AI Foundry, Vertex AI (Claude), Amazon Bedrock.
When was Claude Fable 5.1 released?
Anthropic released Claude Fable 5.1 on 1 Sept 2026, according to models.dev.
Which providers offer Claude Fable 5.1?
We track Claude Fable 5.1 on 7 providers: Claude API, Azure AI Foundry, Vertex AI (Claude), Amazon Bedrock, Google Vertex AI, Vercel AI Gateway, OpenRouter.
Change history
No changes detected since we started tracking this model. We re-check every source daily.
Sources
- https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-fable-5-1.toml
- https://github.com/sst/models.dev/blob/dev/providers/azure/models/claude-fable-5-1.toml
- https://github.com/sst/models.dev/blob/dev/providers/google-vertex-anthropic/models/claude-fable-5-1@default.toml
- https://github.com/sst/models.dev/blob/dev/providers/amazon-bedrock/models/global.anthropic.claude-fable-5-1.toml
- https://github.com/sst/models.dev/blob/dev/providers/amazon-bedrock/models/anthropic.claude-fable-5-1.toml
- https://github.com/sst/models.dev/blob/dev/providers/google-vertex/models/claude-fable-5-1@default.toml
- https://github.com/sst/models.dev/blob/dev/providers/vercel/models/anthropic/claude-fable-5.1.toml
- https://openrouter.ai/anthropic/claude-fable-5.1
- https://github.com/sst/models.dev/blob/dev/providers/amazon-bedrock/models/us.anthropic.claude-fable-5-1.toml