---
title: "Claude Fable 5.1"
description: "Anthropic's model for demanding reasoning and long-horizon agentic work."
canonical: "https://vetted.tools/models/claude-fable-5-1"
source: "https://vetted.tools/models/claude-fable-5-1.md"
---

# Claude Fable 5.1

Anthropic's model for demanding reasoning and long-horizon agentic work.

Source: https://vetted.tools/models/claude-fable-5-1

- Slug: `claude-fable-5-1`
- By [Anthropic](https://vetted.tools/companies/anthropic) ([anthropic.com](https://www.anthropic.com/claude), checked 2026-09-26)
- Official page: [https://www.anthropic.com/claude](https://www.anthropic.com/claude)

## Facts

- Capabilities: Reasoning, Tool use, Explicit caching, File input, Vision, Structured output ([Vercel AI Gateway](https://ai-gateway.vercel.sh/v1/models), checked 2026-09-25)
- Context window: 1M tokens (1,000,000) ([Vercel AI Gateway](https://ai-gateway.vercel.sh/v1/models), checked 2026-09-25)
- Gateway ID: anthropic/claude-fable-5.1 ([Vercel AI Gateway](https://ai-gateway.vercel.sh/v1/models), checked 2026-09-25)
- Input: $10 per 1M tokens ([Vercel AI Gateway](https://ai-gateway.vercel.sh/v1/models), checked 2026-09-25)
- Knowledge cutoff: Jun 2026 ([Vercel AI Gateway](https://ai-gateway.vercel.sh/v1/models), checked 2026-09-25)
- Max output: 128K tokens (128,000) ([Vercel AI Gateway](https://ai-gateway.vercel.sh/v1/models), checked 2026-09-25)
- Takes: Text, image, PDF ([Vercel AI Gateway](https://ai-gateway.vercel.sh/v1/models), checked 2026-09-25)
- Returns: Text ([Vercel AI Gateway](https://ai-gateway.vercel.sh/v1/models), checked 2026-09-25)
- No training on prompts: Offered by every provider on the Vercel AI Gateway, when you turn it on ([Vercel AI Gateway](https://ai-gateway.vercel.sh/v1/models), checked 2026-09-25)
- Output: $50 per 1M tokens ([Vercel AI Gateway](https://ai-gateway.vercel.sh/v1/models), checked 2026-09-25)
- Released: Aug 31, 2026 ([Vercel AI Gateway](https://ai-gateway.vercel.sh/v1/models), checked 2026-09-25)
- Type: Language ([Vercel AI Gateway](https://ai-gateway.vercel.sh/v1/models), checked 2026-09-25)
- Zero data retention: Not offered by any provider on the Vercel AI Gateway ([Vercel AI Gateway](https://ai-gateway.vercel.sh/v1/models), checked 2026-09-25)

## Usage

- 17,032,286 requests and 2,300,667,811,275 tokens on [OpenRouter](https://openrouter.ai/anthropic/claude-fable-5.1) over the 25 days to 2026-09-25.

## Elsewhere on this site

- Home: https://vetted.tools/index.md
- Use cases: https://vetted.tools/use-cases.md
- Tools: https://vetted.tools/tools.md
- The brief: https://vetted.tools/brief.md
- Assessment: https://vetted.tools/assessment.md
- Site summary for agents: https://vetted.tools/llms.txt
- Every published page in one file: https://vetted.tools/llms-full.txt
- Every URL the site publishes: https://vetted.tools/sitemap.xml