Anthropic releases Claude Sonnet 5.5: same price, says 30%+ faster and up to 30% cheaper for most tasks
Anthropic released Claude Sonnet 5.5, the second model in the Claude 5.5 family. The company says it is a clear upgrade over Claude Sonnet 5, generates output 30%+ faster and needs fewer tokens for the same work, costing up to 30% less for most work; API pricing matches Sonnet 5 at $2 per million input tokens and $10 per million output tokens. Everyday users can use it on Claude.ai on the web and in the iOS and Android apps.
Anthropic positions Sonnet 5.5 as a faster, lower-cost complement to Claude Opus 5.5: Opus 5.5 is for complex work requiring careful judgment, while Sonnet 5.5 is strongest at well-scoped everyday tasks, fixing bugs, and creating documents, slides and spreadsheets. Claude Haiku 5.5, for high-volume and cost-sensitive uses, will join the family in the coming weeks.
The company says Sonnet 5.5 scores 70.6% on the Terminal-Bench 4.0 agentic coding evaluation, two points below Opus 5.5 on GDPval-AA, and is the first Sonnet model to beat Pokémon Red working only from screenshots. Anthropic also notes that benchmarks capture only part of a model’s abilities, and that Opus 5.5 remains clearly stronger at complex, open-ended work requiring sustained judgment.
In use, the default effort level is Medium in Claude Code and the Claude apps and High on the Claude Platform; lower settings are faster and use fewer tokens, higher settings reason longer and check more thoroughly.
On safety, because Sonnet 5.5’s cyber capabilities are a large step up from Sonnet 5’s, Anthropic deploys safeguards similar to Opus 5.5’s: routine bug finding and fixing is unaffected, but higher-risk cybersecurity tasks will visibly fall back to Sonnet 5; cyberdefenders will soon be able to apply to an expanded Cyber Verification Program. Biology safeguards are the same as Sonnet 5’s, and some microbiology and virology requests may be flagged in error. It is also the first Sonnet model with classifiers that prevent reasoning extraction, and it expands preserved thinking so Claude’s thinking cannot be decoupled from the account that created it, which affects moving conversations between accounts, including switching accounts mid-session in Claude Code.
Sonnet 5.5 is available on all platforms, including AWS, Google Cloud and Microsoft Azure, under the model name claude-sonnet-5-5; users who ran Sonnet with thinking off must switch to the new between_tools setting before moving to Sonnet 5.5. The Sonnet product page adds that prompt caching saves up to 90% and batch processing 50%, and that US-only inference is available at 1.1x pricing for input and output tokens.
Sources
- Introducing Claude Sonnet 5.5 — Anthropic
- Claude Sonnet — www.anthropic.com