Anthropic introduces Claude Sonnet 5.5 AI model, claims it beats OpenAI GPT 6 Sol in complex knowledge tasks
Follow UsAnthropic has introduced Claude Sonnet 5.5, the second model in its Claude 5.5 family.
Anthropic says Claude Sonnet 5.5 generates responses more than 30 per cent faster than its predecessor.
It also uses fewer tokens to complete many tasks, which can reduce the overall cost by up to 30 per cent.
Anthropic has introduced Claude Sonnet 5.5, the second model in its Claude 5.5 family. The company says the new AI model is faster, more efficient and cheaper to run than Claude Sonnet 5. It is designed for everyday tasks such as coding, creating documents, presentations and spreadsheets. Anthropic also claims that Sonnet 5.5 performs strongly on long-running tasks and knowledge-based work. In one evaluation, the new AI model outperformed OpenAI’s GPT-6 Sol on long-horizon knowledge work, as shared by the company.
SurveyClaude Sonnet 5.5 capabilities
Anthropic says Claude Sonnet 5.5 generates responses more than 30 per cent faster than its predecessor. It also uses fewer tokens to complete many tasks, which can reduce the overall cost by up to 30 per cent.
Coding is one of the areas where Anthropic said Sonnet 5.5 has made the biggest jump. It scored 70.6 per cent on Terminal-Bench 4.0, an agentic coding evaluation, compared with 10.3 per cent for Sonnet 5.
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On GDPval-AA, a benchmark covering tasks across 44 occupations, Sonnet 5.5 is said to have scored nearly as well as Opus 5.5. Anthropic says the new model “clearly outperforms” GPT-6 Sol on long-horizon knowledge work.
Furthermore, Anthropic claims the new AI model is “strongest at well-scoped everyday tasks, fixing bugs, and creating polished documents, slides, and spreadsheets.” Early testers reportedly found it to be a “more natural conversational partner” and praised its design skills, according to the company.
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Introducing Claude Sonnet 5.5, the second model in the Claude 5.5 family.
— Claude (@claudeai) September 28, 2026
It’s a clear upgrade over Sonnet 5, runs more than 30% faster, and costs up to 30% less for most work. pic.twitter.com/UvXD8mDTF1
Claude Sonnet 5.5 availability and pricing
Claude Sonnet 5.5 is now available across Anthropic’s platforms. Developers can access it through the Claude Platform using the model name claude-sonnet-5-5.
It is also available through Amazon Web Services, Google Cloud and Microsoft Azure. Anthropic says the model supports zero data retention.
The new AI model keeps the same API pricing as Sonnet 5. This means it costs $2 per million input tokens and $10 per million output tokens. Cache reads cost $0.20 per million tokens.
