Claude Sonnet 4.5 Released
CONFIRMEDDate confidence: CONFIRMEDStated as firmHow firmly the source words the date: confirmed, scheduled, estimated, delayed or unverified.Show all CONFIRMED pins89% CONFIDENCEOverall confidence: 89%How well the pin's source and references back up its dates.Weighted average of how firmly 5 references, the source included, support the pin's start and end times; a reference counts half as much for every 180 days older than the newestShow all pins at 75% confidence or betterThe post is dated "Sep 29, 2025" and says "Claude[2] Sonnet 4.5 is available everywhere today"; the docs model page lists "Released September 29, 2025" and TechCrunch[4] reports the launch "On Monday".
Anthropic releases Claude Sonnet 4.5, which it calls the best coding model in the world at 77.2% on SWE-bench Verified, leads OSWorld computer use at 61.4% and keeps working on one task for more than 30 hours.
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