Anthropic ships its new flagship 20% cheaper, performance claims still self-tested
Opus 5.5 output pricing drops to $20 per million tokens; Anthropic says it beats its own larger model, pending independent verification.
Original event 2026-09-22
This is an archived article. Forecasts, prices and upcoming events refer to its original time period.
Anthropic released Opus 5.5 on September 22, cutting output token pricing to $20 per million tokens from $25 for the previous model, a 20% drop.
The company calls it the strongest-performing model it has tested and says it outpaces its own larger Fable model on many benchmarks. Those results are all vendor-run; METR and other outside groups did pre-release safety evaluation only, and no independent performance verification exists yet.
Anthropic says the model is comparable to Mythos in biology and cybersecurity capabilities, so it carries the same usage safeguards as Fable. Sonnet 5.5 and Haiku 5.5 are promised in the coming weeks; whether the price cut extends to mid-tier models is what buyers should watch.