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Anthropic releases Claude Opus 5.5 with enhanced safeguards and reduced pricing

The upgraded AI model cuts token costs while maintaining specialized protections for biology and cybersecurity.

Updated Sep 22, 2026 · 19:19 UTC5 reports

The short version

  • Anthropic launched Claude Opus 5.5, marking its first model release since the company called for pacing frontier AI development.[Hacker News · Hacker News · The Verge · 9to5Mac]
  • The new model features a 1 million token context window, lower compute demands, and reduced API pricing for input, output, and cache read tokens.[Hacker News · Hacker News · 9to5Mac]
  • Pre-release safety evaluations were conducted by external groups including METR and Frontier Design, with additional Sonnet 5.5 and Haiku 5.5 models scheduled in the coming weeks.[Hacker News · TechCrunch · 9to5Mac]

Key facts

  • Anthropic released Claude Opus 5.5 on September 22, 2026, featuring a 1 million token context window.[Hacker News · Hacker News]
  • API pricing is set at $4 per million input tokens, $20 per million output tokens, and $0.20 per million cache reads.[Hacker News · 9to5Mac]
  • Anthropic reports Opus 5.5 requires less compute than Opus 5 and costs 40% less on typical workloads at default settings.[9to5Mac]
  • The model underwent pre-release testing by external evaluators including METR and Frontier Design.[Hacker News · 9to5Mac]
  • Anthropic states that Claude Sonnet 5.5 and Claude Haiku 5.5 will follow in the coming weeks.[TechCrunch · 9to5Mac]

Sources

Outlet counts describe coverage, not independent confirmation. Reports may share a wire service or original source.