Claude Sonnet 4.5
Anthropic's most capable model with breakthrough performance across all tasks
Claude Sonnet 4.5
Anthropic • September 2025
Training Data
Up to April 2024
Claude Sonnet 4.5
September 2025
Parameters
~300 billion
Training Method
Constitutional AI
Context Window
200,000 tokens
Knowledge Cutoff
April 2024
Key Features
State-of-the-art Performance • Advanced Reasoning • Superior Coding
Capabilities
Reasoning: Outstanding
Coding: Outstanding
Multimodal: Excellent
What's New in This Version
Breakthrough performance with significant improvements in reasoning and coding
Anthropic's most capable model with breakthrough performance across all tasks
What's New in This Version
Breakthrough performance with significant improvements in reasoning and coding
Technical Specifications
Key Features
Capabilities
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