Skip to content

Anthropic launches Claude Sonnet 5.5, claiming faster, cheaper performance than Sonnet 5

Sep 29, 2026
The Deep View
Article image for Anthropic launches Claude Sonnet 5.5, claiming faster, cheaper performance than Sonnet 5

Summary

Anthropic launches Claude Sonnet 5.5, saying the new model runs 30% faster and costs up to 30% less than Sonnet 5 while surpassing both Sonnet 5 and Opus 5.5 on Terminal-Bench 4.0 agentic-coding tests.

Key Points

  • Anthropic releases Claude Sonnet 5.5 as a lower-cost, faster complement to Opus 5.5.
  • Anthropic says Sonnet 5.5 runs 30% faster than Sonnet 5 and uses fewer tokens, cutting costs by up to 30% for most tasks.
  • Sonnet 5.5 scores above both Sonnet 5 and Opus 5.5 on Terminal-Bench 4.0 for agentic coding and adds Opus 5-level cybersecurity safeguards.

Tags

Read Original Article