Anthropic
LLM
Medium
Closed weights
Claude Sonnet 5.5
45 days since Anthropic announced it ·
Claude Sonnet 5.5 is a closed-weights LLM from Anthropic, announced 28 Sep 2026. It costs $2 per 1M input tokens and $10 per 1M output tokens. Its context window is 1M tokens.
- Input
- $2
- per 1M tokens
- Cache write
- $2.50
- per 1M tokens
- Cache read
- $0.10
- per 1M tokens
- Output
- $10
- per 1M tokens
- Context window
- 1M
- tokens
- Parameters
- —
- not disclosed
- Announcement
- anthropic.com/claude-sonnet-5-5
- Docs
- platform.claude.com/docs/en/models/sonnet-5-5/overview
Our coverage
2 storiesAnthropic · Medium
closed weights- Claude Sonnet 5.5 +90d
- Claude Sonnet 5 +133d
- Claude Sonnet 4.6 +141d
- Claude Sonnet 4.5
More from Anthropic
All models- Claude Mythos 5.2
- Claude Fable 5.2
- Claude Haiku 5.5
- Claude Opus 5.5
- Claude Mythos 5.1
- Claude Fable 5.1
- Claude Opus 5
- Claude Mythos 5
Tools that picked it up
- Claude same day
- Claude Code 2.1.284 same day
Facts last updated , from Anthropic’s own pages.