CodingAnthropic Launches Claude Sonnet 5.5: 70.6% Terminal Coding at 30% Faster SpeedsAnthropic has released Claude Sonnet 5.5, the second model in the Claude 5.5 family. Achieving a record 70.6% on Terminal-Bench 4.0, Sonnet 5.5 cuts per-task costs by up to 30% and accelerates output generation speeds by more than 30%.29 Sep 2026 · 4 min