Claude Fable 5

Anthropic · June 2026

The most capable Claude. Handles hard problems, long documents, and work that runs over many steps.

Best for: Coding, deep reasoning, and agent workflows

Context window
1,000,000 tokens
≈ 750,000 words · about 3,000 pages
Max output
128,000 tokens
≈ 96,000 words in a single answer
Knowledge cutoff
January 2026
its training cutoff

Modalities

TextInput and output
ImageInput only
AudioNot supported
VideoNot supported

Reasoning effort

Default: High.

Low
Medium
High
X-High
Max

Features

StreamingSupported
Function callingSupported
Structured outputsSupported
Fine-tuningNot supported

Tools

Web searchSupported
Code interpreterSupported

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