Claude Sonnet 5.5 Released
CONFIRMEDDate confidence: CONFIRMEDStated as firmHow firmly the source words the date: confirmed, scheduled, estimated, delayed or unverified.Show all CONFIRMED pins86% CONFIDENCEOverall confidence: 86%How well the pin's source and references back up its dates.Weighted average of how firmly 6 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 betterAnthropic's[1] announcement is headed "Claude[4] Sonnet 5.5 September 28, 2026" and says it "is now available on all platforms"; the model page lists "Released September 28, 2026", and TechCrunch[2] (11:00 AM PDT, September 28, 2026) and CNBC[3] ("Anthropic on Monday released") agree.
Anthropic releases Claude Sonnet 5.5, the second model in its Claude 5.5 family, which it says runs more than 30% faster than Sonnet 5 and costs up to 30% less per task at the same $2 and $10 per million token prices.