Anthropic released Claude Opus 5.5 on September 22, 2026, with token prices below those of its predecessor. The company says the artificial intelligence model offers performance comparable to its top-tier Fable 5.1.
The San Francisco-based developer set pricing at $4 per million input tokens and $20 per million output tokens. Those rates are 20% below Opus 5’s prices, according to Anthropic’s product page.
Separately, Anthropic estimates that running typical workloads costs around 40% less than with the previous model. That estimate measures usage costs rather than the reduction in standard token prices.
By comparison, Fable 5.1 costs $10 per million input tokens and $50 per million output tokens. Customers can access the new model through Amazon Web Services and Google Cloud.
Anthropic also claims the model outperformed OpenAI’s GPT-5.6 Sol on a software development benchmark. It put the cost of that work at roughly one-third of its rival’s.
In safety evaluations, the company reported about 85% fewer attempts to bypass containment boundaries than with Opus 5 or Mythos 5.1. Independent organisations carried out external testing.
Read: OpenAI Ethical Hack Used Claude to Reach Private Code Repo
The release follows preparations for an initial public offering planned for autumn 2026, the Financial Times reported. The newspaper put Anthropic’s valuation at $965 billion. Investors are awaiting its prospectus to assess growth prospects and competition.
