Anthropic has released Claude Sonnet 5.5, the latest addition to its Claude 5.5 family, promising faster performance and lower costs for everyday AI tasks including coding, document creation, presentations and spreadsheets.
The company said Sonnet 5.5 generates responses more than 30% faster than its predecessor, Sonnet 5, while typically costing up to 30% less per task because it uses fewer tokens to complete the same work.
Sonnet sits between Anthropic’s more capable Opus models and its smaller Haiku models in the company’s model lineup.
Faster and cheaper than Sonnet 5
Anthropic said Sonnet 5.5 is its fastest Sonnet model yet and is intended for well-scoped tasks that benefit from quick iteration.
The model retains the same API pricing as Sonnet 5 at $2 per million input tokens and $10 per million output tokens, but Anthropic says its greater efficiency can reduce the overall cost of completing a task by up to 30%.
The company said Sonnet 5.5 is particularly suited to everyday coding, fixing bugs and producing polished office documents, slides and spreadsheets.
Stronger coding performance
Anthropic is also highlighting improvements in agentic coding, where AI systems can independently use tools and perform multiple steps to complete a task.
The company reported a score of 70.6% on Terminal-Bench 4.0, compared with 10.3% for Sonnet 5 in its testing. Anthropic also said Sonnet 5.5 performed strongly on longer-running tasks and image understanding.
Anthropic said the model can also perform particularly well when multiple agents are used within cost constraints, making its speed and efficiency important for software development workflows.
Cybersecurity safeguards expanded
Sonnet 5.5 also brings stronger cybersecurity capabilities, according to Anthropic.
The company said its cyber capabilities are comparable to those of Opus 5 and that Sonnet 5.5 is therefore the first Sonnet model to launch with the cybersecurity safeguards and fallback mechanisms used for Anthropic’s most capable models.
Anthropic said the safeguards target a narrow range of high-risk requests and do not affect routine software development or most life sciences work.
Haiku 5.5 coming soon
Anthropic said Claude Haiku 5.5, the smaller and more cost-focused model in the Claude family, will be released in the coming weeks.
The launch follows the release of Claude Opus 5.5 on September 22. Anthropic has been rapidly expanding its Claude 5.5 lineup, with Opus aimed at more complex work and Sonnet positioned as a faster option for everyday tasks.
Claude Sonnet 5.5 is now available through Claude’s web, iOS and Android apps, as well as Anthropic’s developer platform and major cloud providers including Amazon Web Services, Google Cloud and Microsoft Azure.
