ReleasedSep 29, 2025 ·
Claude Sonnet 4.5 is out
Anthropic shipped Claude Sonnet 4.5.
AnthropicAnthropic released Claude Sonnet 4.5 on Sep 29, 2025.
It follows Claude Sonnet 4, 130 days earlier. Releases in the Claude Sonnet line usually land about 130 days apart.
Claude Sonnet 4.6 replaced it on Feb 17, 2026.
Released
Sep 29, 2025
Line
Claude Sonnet
Previous
Claude Sonnet 4 (May 22, 2025)
Confirmed by
Historical record
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