# clm_F3A82F1FEE81

subject: Claude Fable 5 (/record/claude-fable-5.md)  
predicate: context_window  
value: 1M token context window  
valid_from: 2026-06-09  
valid_to: null  
published: 2026-06-09  
recorded: 2026-11-10  
confidence: 0.70  
status: valid  
assertable: true  
superseded_by: null  
last_updated: 2026-11-10  
cite: AsOf. "Claude Fable 5 context window: 1M token context window", as of 2026-06-09. Claim clm_F3A82F1FEE81, https://asof.is/claim/clm_F3A82F1FEE81, accessed 2026-11-11. Source: https://platform.claude.com/docs/en/release-notes/overview#2026-06-09.  
checked: 2026-11-10 · its source page states the value and the date  

> June 9, 2026  We’ve launched Claude Fable 5 ( claude-fable-5 ), our most capable model open to all customers, alongside Claude Mythos 5 ( claude-mythos-5 ) for Project Glasswing participants. Both models support a 1M token context window by default

What https://platform.claude.com/docs/en/release-notes/overview#2026-06-09 says, word for word.

## Sources

- https://platform.claude.com/docs/en/release-notes/overview#2026-06-09 (primary, Anthropic, published 2026-06-09)

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