Claude Sonnet 5.5

Anthropic

Claude Sonnet 5.5 is a clear upgrade over Claude Sonnet 5, runs 30%+ faster, and costs up to 30% less for most work.

Specs

Model

Family
Claude
Variant
Sonnet 5.5
Weights
Proprietary

Limits

Context
1,000,000 tokens
Max output
128,000 tokens

Modalities

Input
Text Image PDF
Output
Text

Pricing

Input
$2 / 1M
Output
$10 / 1M
Cache read
$0.2 / 1M
Cache write
$2.5 / 1M

Capabilities

Reasoning
Yes
Reasoning control
Effort levels
Tool calling
Yes
Attachments
Yes

Dates

Released
28 Sept 2026
Knowledge cutoff
Jun 2026

Introducing Claude Sonnet 5.5

Claude Sonnet 5.5 is a clear upgrade over Claude Sonnet 5, runs 30%+ faster, and costs up to 30% less for most work.

Anthropic
anthropic.com

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