Prior Sonnet-tier model balancing speed and intelligence, now legacy. Provides a 1M-token context window with extended thinking and vision at the standard Sonnet price of $3/$15 per million tokens.
profile normalized against the 47-model field
Context window· 1M of 1.05M95%
Max output· 64K of 272K24%
Output speed· 85 tok/s27%
Affordability· $15.00 / Mtok out92%
Capability breadth· 4 of 1136%
Capability switches · 4 of 11
Reasoning mode
Tool / function use
Streaming
JSON mode
Structured outputs
Prompt caching
Fine-tuning
Web search
Code execution
Vision input
Audio input
Specifications
Every value carries a primary source and a verification date.
Capacity
Context window
1M
Max output
64K
Pricing
Input $/Mtok
$3.00 / Mtok input USD/Mtok
Cached input $/Mtok
0.3 USD/Mtok
Output $/Mtok
$15.00 / Mtok output USD/Mtok
Performance
Output speed
85 tok/s tok/s
Capabilities
Input modalities
Text, image
Output modalities
Text
Reasoning mode
Extended thinking: Yes
Tool / function use
Yes
Prompt caching
Yes
Vision input
Yes
API
API model ID
claude-sonnet-4-5
Batch API
Yes
General
Knowledge cutoff
January 2025
Release date
September 29, 2025
Benchmarks
Sourced evaluation scores, each verified against its primary source.
GPQA Diamond
Claude Sonnet 4.5 reaches GPQA Diamond: 80.6%.
80.6 %Verified
SWE-bench Verified
On SWE-bench Verified, Claude Sonnet 4.5 scores 73.1%.
73.1 %Verified
Humanity's Last Exam (no tools)
Humanity's Last Exam (no tools): 12.8% for Claude Sonnet 4.5.