Sonnet 5.5 released
The gist
Anthropic released Claude Sonnet 5.5 on September 28, 2026, priced at $2 per million input tokens.
It is the cheaper, faster option for routine work, not complex tasks.
How it unfolded
- Sep 22, 2026Anthropic released Opus 5.5; its documentation said Sonnet 5.5 and Haiku 5.5 would launch in the coming weeks.
- Sep 28, 2026Anthropic announced Claude Sonnet 5.5, available on all platforms including Amazon Web Services, Google Cloud and Microsoft Azure.
- Sep 28, 2026Sonnet 5.5 was priced at $2 per million input tokens, $10 per million output tokens, $0.20 per million cache reads, and $2.50 per million cache writes.