Claude Sonnet 5.5

Anthropic's faster, cheaper Claude 5.5-family model, generating output 30% faster than Sonnet 5 at unchanged pricing.

Anthropic · Frontier/foundation models · model

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Overview

Anthropic released Claude Sonnet 5.5 on September 28, 2026, the second model in the Claude 5.5 family after Claude Opus 5.5. Anthropic says it generates output more than 30% faster while costing up to 30% less per task than Sonnet 5, due to fewer tool calls and faster inference, at unchanged pricing of $2/million input and $10/million output tokens. Anthropic positions it as strongest at well-scoped everyday tasks, bug fixes, and polished documents, slides, and spreadsheets, and says it is the first Sonnet model to beat Pokemon Red working only from screenshots. The model ships with invisible text watermarking to help detect AI-generated content and is available under model ID claude-sonnet-5-5 on Anthropic's API, AWS, Google Cloud, and Microsoft Azure.

This is a sourced directory entry. Features and capabilities are reported in the linked sources; this entry does not document independent Aymorphic testing.

Key features

  • Output more than 30% faster than Claude Sonnet 5, with up to 30% lower cost per task
  • 70.6% on Terminal-Bench 4.0 at unchanged $2/$10 per-million-token pricing
  • First Sonnet model reported to beat Pokemon Red from screenshots alone
  • Invisible text watermarking built in to help detect AI-generated content
  • Available on Anthropic's API plus AWS, Google Cloud, and Microsoft Azure

Use cases

  • Well-scoped everyday coding tasks and bug fixes
  • Producing polished documents, slides, and spreadsheets
  • Cost-sensitive workloads needing faster inference than Sonnet 5
  • Cloud-hosted deployment across AWS, Google Cloud, or Azure

Pricing

$2/million input tokens, $10/million output tokens -- unchanged from Claude Sonnet 5.

Pricing reflects the source record and may change. Confirm current terms with the provider.

Dates and sources

Released
28 Sept 2026
Record updated
29 Sept 2026
Record last checked
29 Sept 2026

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