Claude Sonnet 4.5
Parameters
Undisclosed
Context Length
200K
Modality
Text
Architecture
Undisclosed
License
Proprietary
Release Date
29 Sept 2025
Knowledge Cutoff
Jan 2025
API Pricing (per 1M)
Input: $3.00 · Output: $15.00
Evaluation Benchmarks
Rank
#64
| Benchmark | Score | Rank |
|---|---|---|
Software Engineering | 0.75 | 8 |
StackUnseen | 0.694 | 18 |
LiveBench Average | high (32k) 0.73 | 44 |
Graduate-Level QA | 0.834 | 52 |
General Text | high (32k) 1457 Standard 1455 | 54 58 |
Web Development | high (32k) 1393 Standard 1384 | 79 82 |
Coding Index | auto 0.52 | 84 |
Agentic Index | auto 0.16 | 94 |
Intelligence Index | 0.19 | 165 |
Rankings
Overall Rank
#64
Coding Rank
#64
About Claude Sonnet 4.5
Claude Sonnet 4.5 is a production-grade multimodal model from Anthropic built for agentic execution, codebase refactoring, and parallel tool calling. It delivers fast, dependable reasoning with support for extended 1M token beta contexts.
Technical Specifications
Architecture specifications are undisclosed for proprietary models.
Resources
About Claude 4.5
Enhanced Claude models with further improvements in reasoning, coding, and agentic capabilities. Features advanced thinking modes with adjustable effort levels (high, medium, standard) for optimal performance-latency tradeoffs. Excels at complex analysis, software development, web development, and long-context understanding. Includes thinking variants that expose reasoning process for improved transparency.