Claude Sonnet 5.5
Anthropic · released 28 Sep 2026 · proprietary API
- 1M context
- Text + image in
The best combination of speed and intelligence in the Claude 5 family; supersedes Claude Sonnet 5.
Context window
1M
1,000,000 tokens
Input price
$2
per 1M tokens
Output price
$10
per 1M tokens
Blended
$4
3:1 in:out mix
Weights
Proprietary
API only
Released
28 Sep 2026
Anthropic
Long-context / tier pricing — Cache reads $0.20/1M, the standard 0.1x of base input (Fable 5.1 gets 0.025x, Opus 5.5 0.05x). Default effort high; adaptive thinking. Uses the post-4.7 tokenizer, about 30% more tokens for the same text. Listed prices are the base rate for prompts up to ~200K tokens.
Where it ranks
Of 42 models tracked.
Cost to run
#26(tied)
of 42
Input price
#22(tied)
of 42
Context window
#10(tied)
of 42
Compare with
The nearest models by blended cost to run.
Put it to work
Specs from BitByteCore's hand-verified Frontier Ledger (v2026-10-01), this row verified 1 Oct 2026 against Anthropic's official pricing ↗. Model pricing moves fast, so confirm with Anthropic before you rely on a figure.