Claude Fable 5 Ships as Anthropic's New Top-Ranked Model

Anthropic made Claude Fable 5 generally available on June 9, 2026, alongside the invitation-only Claude Mythos 5 offered through Project Glasswing. Fable 5 is positioned above Claude Opus 5 in Anthropic's own lineup for workloads that "need the highest available capability."

The model runs always-on adaptive thinking - it cannot be switched to a faster, lower-thinking mode the way Opus 5 and Sonnet 5 can - and Anthropic's own model comparison table rates its latency as "Slower," the only model in the current lineup with that rating.

On LMArena's text leaderboard Claude Fable 5 has 1504 Elo (rank 6, high effort). It also scores 62 on the Artificial Analysis Intelligence Index v4.1.1, one point behind Opus 5's 63.

Pricing is $10 input / $50 output per 1M tokens - double Opus 5's rate - with a 1M token context window and 128k max output, available via the Claude API, Amazon Bedrock, Google Cloud, and Microsoft Foundry.