Anthropic unveils Claude Opus 5.5, says performance comparable to top-tier Fable 5.1

Anthropic unveils Claude Opus 5.5, notes performance comparable to top-tier Fable 5.1.

Key points

• Opus 5.5 is priced at $4 per million input tokens and $20 per million output tokens, 20pc below Opus 5, Anthropic remarked.
• According to Anthropic, Opus 5.5 outscored rival OpenAI's GPT-5.6 Sol on a software development benchmark while costing roughly one-third as much to run.
• The model is available on platforms including Amazon Web Services, Google Cloud and Microsoft Azure.
• The release lands against the backdrop of growing debate over AI risks.

Anthropic unveils Claude Opus 5.5, notes performance comparable to top-tier Fable 5.1. Reuters Published September 22, 2026 Updated September 22, 2026 10: 25pm. Join our Whatsapp Channel. Add Dawn as a trusted source.

Anthropic on Tuesday introduced Claude Opus 5.5, a new AI model that it states delivers performance comparable to its top-tier Fable 5.1 while costing 4o per cent less to run than its predecessor.

Meanwhile, the release lands against the backdrop of growing debate over AI risks. Anthropic Chief Executive Officer Dario Amodei earlier this month called on the global AI community to slow down the pace of releasing new capabilities to address safety reservations.

Anthropic remarked Opus 5.5 underwent external testing by independent AI safety research groups Frontier Design and METR before launch and includes safeguards previously reserved for its most capable systems.

Notably, the model is available on platforms including Amazon Web Services, Google Cloud and Microsoft Azure.

Meanwhile, the model additionally scored better than previous systems in internal safety tests and was concerning 85pc less probable than Opus 5 or Mythos 5.1 to attempt to bypass containment boundaries in a dedicated evaluation, the firm stated.

Claude Sonnet 5.5 and Claude Haiku 5.5 will be published in the coming weeks, the firm stated, bringing numerous of the same performance, speed and safety improvements.

Anthropic is additionally expanding programmes that provide vetted cybersecurity and life-sciences researchers broader access to the model.

For now, anthropic unveils Claude Opus 5.5, says performance comparable to top remains the part of the story worth watching, and further updates are likely as more details are confirmed.