Anthropic launches Claude Opus 5.5: Fable 5.1-level performance at 40% lower cost
neilhoulsby · x · 2026-09-23
Anthropic officially introduced Claude Opus 5.5, the first model in its new Claude 5.5 family. Per the announcement, it performs at the level of Claude Fable 5.1 for most tasks and costs 40% less to run than Opus 5. Anthropic researchers (ehsanik, retweeted by Neil Houlsby) praised its visual capabilities as the coolest model release since they joined the company.
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