Anthropic LLM Big Closed weights

Claude Fable 5

156 days since Anthropic announced it · 9 Jun 2026

Claude Fable 5 is a closed-weights LLM from Anthropic, announced 9 Jun 2026. It costs $10 per 1M input tokens and $50 per 1M output tokens. Its context window is 1M tokens.

Input: $10; per 1M tokens
Cache write: $12.50; per 1M tokens
Cache read: $1; per 1M tokens
Output: $50; per 1M tokens
Context window: 1M; tokens
Parameters: —; not disclosed

Announcement: anthropic.com/news/claude-fable-5-mythos-5
Docs: platform.claude.com/docs/en/models/fable-5/overview

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Anthropic · Big · Fable

closed weights

Claude Fable 5.2 +69d 9 Nov 2026
Claude Fable 5.1 +84d 1 Sep 2026
Claude Fable 5 9 Jun 2026