Anthropic launches Claude Sonnet 5.5: 30% faster with up to 30% lower effective cost
ClaudeOfficial · reddit · 2026-09-29
Anthropic has released Claude Sonnet 5.5, the second model in the Claude 5.5 family, positioned as a faster, cheaper complement to Opus 5.5 for well-scoped everyday tasks: bug fixing, polished documents, slides, and spreadsheets, with a strong design sense.
Key points:
- Over 30% faster than Sonnet 5, with up to 30% lower effective cost for most work — same per-token price, but it needs far fewer tokens for the same task
- Writes more clearly than the previous generation; its speed suits fast iteration
- Automated behavioral audits show improvements over Sonnet 5 on most alignment and honesty measures
- First Sonnet with cybersecurity safeguards comparable to Anthropic's most capable models; routine software development is unaffected
- Available everywhere today; Claude Haiku 5.5 will follow in the coming weeks
Related event: Anthropic Launches Claude Sonnet 5.5: Over 30% Faster, Up to 30% Cheaper(58 posts)→
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