Opus 5.5 Is 40% Cheaper and 30% Faster; Haiku 5.5 Coming in Weeks

kimmonismus · x · 2026-09-23

@kimmonismus sums up Opus 5.5: 40% cheaper than Opus 5, Fable 5.1-level performance, 30% faster output, plus a quota reset — reading it as Anthropic declaring war on OpenAI.

He also says earlier rumors were wrong: Haiku 5.5 will be released in the coming weeks (unconfirmed), crediting Anthropic for listening to the community.

Related event: Anthropic Launches Claude Opus 5.5: Smarter, Faster and 40% Cheaper(55 posts)→

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