Nundina › Discover calendars › Version End-of-Life Dates calendar › Claude Sonnet 4.5 ends active supportClaude Sonnet 4.5 ends active support30 September 2026Claude Sonnet 4.5 stops receiving fixes and new features, though security support may continue. Released 29 Sep 2025. Source: endoflife.date.Version End-of-Life Dates calendarMore from this calendar