Claude Sonnet 4.5
Parameters
-
Context Length
200K
Modality
Text
Architecture
Dense
License
Proprietary
Release Date
29 Sept 2025
Knowledge Cutoff
-
Technical Specifications
Attention Structure
Multi-Head Attention
Hidden Dimension Size
-
Number of Layers
-
Attention Heads
-
Key-Value Heads
-
Activation Function
-
Normalization
-
Position Embedding
Absolute Position Embedding
Claude Sonnet 4.5
Fast and capable Claude 4.5 Sonnet without thinking mode for efficient performance. Strong coding capabilities (76.07 LiveBench Coding) and solid language understanding (76.00). Good web development performance (Elo 1386). Optimized for production workloads requiring balance of quality and speed. Popular choice for general-purpose applications.
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.
Other Claude 4.5 Models
Evaluation Benchmarks
Rank
#16
| Benchmark | Score | Rank |
|---|---|---|
General Knowledge MMLU | 0.90 | 🥈 2 |
Coding Aider Coding | 0.77 | 🥉 3 |
Coding LiveBench Coding | 0.76 | 10 |
Agentic Coding LiveBench Agentic | 0.54 | 15 |
Web Development WebDev Arena | 1386 | 19 |
Mathematics LiveBench Mathematics | 0.57 | 41 |
Reasoning LiveBench Reasoning | 0.42 | 43 |
Rankings
Overall Rank
#16
Coding Rank
#7