Release dates
— Anthropic launched Claude Sonnet 5.5 as the second model in the Claude 5.5 family; API model ID `claude-sonnet-5-5`, available on Claude, AWS, Google Cloud, and Microsoft Azure. ↗
Claude Sonnet 5.5
The second model in the Claude 5.5 family and a faster, more efficient upgrade to Sonnet 5 for everyday coding, agent work, and professional documents.
Anthropic launched Claude Sonnet 5.5 on 2026-09-28 with API ID `claude-sonnet-5-5` available to all Claude API customers and on Amazon Bedrock, Google Cloud, Microsoft Foundry, and Claude Platform on AWS; high-risk cybersecurity requests may fall back to Sonnet 5.
MODEL NUMBER084
- First public date
- 2026-09-28
- Organization
- Anthropic
- Family
- Claude
01
Specifications
Only published specifications are shown.
02
Overview
Why it mattered
Anthropic reports 30%+ faster output and up to 30% lower per-task cost than Sonnet 5; it is the first Sonnet model with safeguards and fallbacks for high-risk cybersecurity tasks.
PreviousClaude Sonnet 5— · 1M ctx
CurrentClaude Sonnet 5.5— · 1M ctx
04
Architecture & capabilities
Model capabilities
Adaptive reasoningCodingAgentVisual reasoning
Connected tools
Computer use
Product features
Professional work
05
Release history
Anthropic launched Claude Sonnet 5.5 as the second model in the Claude 5.5 family; API model ID `claude-sonnet-5-5`, available on Claude, AWS, Google Cloud, and Microsoft Azure.
View source06
Related models
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07
Sources
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