Claude Sonnet 5.5
Well-scoped everyday coding and knowledge work at the best speed-intelligence balance.
Claude Sonnet 5.5 supersedes Claude Sonnet 5.
What are Claude Sonnet 5.5's specs and price?
Claude Sonnet 5.5, built by Anthropic, ships a 1M-token context window and a 128K-token max output, released 2026-09. It supports text and vision input with a dedicated reasoning mode and costs $4.00 per million blended tokens, the 42nd-cheapest of 49 models we track.
What are Claude Sonnet 5.5's specs?
| Context window | 1M tokens |
| Max output | 128K tokens |
| Modalities | text, vision |
| Extended thinking | Yes |
| Released | 2026-09 |
| Knowledge cutoff | 2026-06 |
| Provider | Anthropic |
Verified 2026-10-01 — source.
Where does Claude Sonnet 5.5 rank?
What are Claude Sonnet 5.5's strengths?
- 30% faster output than Sonnet 5
- Up to 30% lower cost per task at the same token price
- Beats Opus 5.5 on agentic coding evals
What else should you know about Claude Sonnet 5.5?
What are common questions about Claude Sonnet 5.5?
What is Claude Sonnet 5.5's context window?
Claude Sonnet 5.5 has a 1M-token context window and a 128K-token max output — the 14th-largest context of the 49 current models we track. Source: https://platform.claude.com/docs/en/models/sonnet-5-5/overview, verified 2026-10-01.
Does Claude Sonnet 5.5 support vision or audio input?
Yes — Claude Sonnet 5.5 accepts vision input in addition to text.
Does Claude Sonnet 5.5 have a reasoning or extended-thinking mode?
Yes — Claude Sonnet 5.5 exposes a dedicated reasoning mode for multi-step problems.
When was Claude Sonnet 5.5 released, and what is its knowledge cutoff?
Claude Sonnet 5.5 was released 2026-09 with a knowledge cutoff of 2026-06.
How much does Claude Sonnet 5.5 cost, and who provides it?
Claude Sonnet 5.5 is served by Anthropic at $4.00/M blended tokens (3:1 input:output) — the 42nd-cheapest of 49 current models. Full pricing breakdown: /llm-api-pricing/claude-sonnet-5-5.