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Anthropic takes Claude Opus 5.5 fast mode out of research preview
On Oct 15, Anthropic's Claude Platform release notes say fast mode for Claude Opus 5.5 is out of research preview: you no longer need to request access or send the fast-mode-2026-02-01 beta header (requests that still send it keep working). Opus 5.5 now has a default fast mode rate limit on the Start, Build and Scale usage tiers. Anthropic's pricing page lists Opus 5.5 fast mode at $8 input / $40 output per million tokens (standard Opus 5.5 is $4 / $20). Anthropic says fast mode can run at up to 2.5x standard output speed. Fast mode for Opus 5 and Opus 4.8 stays in research preview. Opus 5.5 fast mode is also available on Claude in Microsoft Foundry for Azure-hosted deployments.
How you’d use it: If you already use Opus 5.5 and need faster streamed output, turn on fast mode without a waitlist; budget for the higher per-token price.