Claude Opus 5.5 cuts costs 40%
The gist
Anthropic released Claude Opus 5.5, saying it costs 40% less to run than Opus 5.
The cheaper model lands as Anthropic reportedly prepares a November IPO.
How it unfolded
- Sep 18, 2026Reports said Anthropic planned a November IPO, later than the October debut many investors expected, possibly to share third-quarter financials; reports also said it was considering a new AI model before going public.
- Sep 21, 2026Reports said a growing number of software companies are turning to open-weight AI models, including Chinese ones, due to the cost of proprietary models from U.S. developers.
- Sep 22, 2026Anthropic released Claude Opus 5.5, saying it matches Claude Fable 5.1 on most work and costs 40% less to run than Opus 5; API pricing was set at $4 per million input tokens and $20 per million output tokens, both 20% below Opus 5.