Claude Sonnet 4.5
Anthropic • LLM
Claude Sonnet 4.5 is Anthropic’s most advanced Sonnet model to date, optimized for real-world agents and coding workflows. It delivers state-of-the-art performance on coding benchmarks such as SWE-bench Verified, with...
Specifications
Context Window
1.0M tokens
Input Price/1M
$3.00
Output Price/1M
$15.00
Parameters
—
Max Output
64K tokens
Benchmarks
Claude Sonnet 4.5 results on the main AI model evaluation benchmarks. Higher scores indicate better performance.
Coding
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| LiveBench Coding | 76.1 | 100.0 | Contamination-free benchmark with objective ground-truth answers |
Data Analysis
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| LiveBench Data Analysis | 47.0 | 100.0 | Contamination-free benchmark with objective ground-truth answers |
Language
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| LiveBench Language | 76.0 | 100.0 | Contamination-free benchmark with objective ground-truth answers |
Math
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| LiveBench Math | 62.6 | 100.0 | Contamination-free benchmark with objective ground-truth answers |
overall
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| LMArena Elo | 1399.0 | 2000.0 | Crowdsourced blind pairwise comparisons |
| LiveBench Global | 53.7 | 100.0 | Contamination-free benchmark with objective ground-truth answers |
Reasoning
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| LiveBench Reasoning | 42.3 | 100.0 | Contamination-free benchmark with objective ground-truth answers |
Information
- Release date
- September 29, 2025
- Tool Calling
- ✅ Supported
- Vision
- ✅ Supported
- Audio
- ❌ Not supported
Full Analysis: Claude Sonnet 4.5
What is Claude Sonnet 4.5?
Claude Sonnet 4.5 is an AI model developed by Anthropic, classified as a large language model (LLM). It is a multimodal model, capable of processing text, images, and potentially other media types. As a proprietary model, it is available via Anthropic's cloud API. With a context window of 1.0M tokens, it is suitable for processing long documents such as contracts, books, and complete codebases.
Pricing & Costs in 2026
Claude Sonnet 4.5 is usage-based, priced at $3/1M input tokens and $15/1M output tokens. For context: 1 million tokens is approximately 750,000 words, or about 10 average-length books. The mid-range pricing balances quality and cost for most professional applications.
Benchmarks & Performance
Claude Sonnet 4.5 was evaluated on 7 different benchmarks, covering categories like Coding, Data Analysis, Language, Math, overall, Reasoning. Results show exceptional performance across available evaluations.
It's important to note that benchmarks measure specific aspects and don't capture the full user experience. Factors like instruction adherence, behavior in long conversations, and real-world task quality vary significantly between models and aren't always reflected in standard scores.
Recommended Use Cases
Claude Sonnet 4.5 is suitable for a wide range of AI applications: long document analysis (contracts, legal proceedings, codebases), automation with tool calling (API integration, databases, external systems), image and visual document analysis (OCR, diagrams, screenshots), multimodal processing combining text and images, complex reasoning, math problem solving, and logical analysis, text generation, summarization, translation, and general assistance.
Comparison with Alternatives
In the 2026 AI model ecosystem, Claude Sonnet 4.5 competes directly with similarly capable models. Key competitors include GPT (OpenAI), Gemini (Google), and open source models like Llama (Meta) and DeepSeek. The choice between models depends on the specific use case, budget, latency requirements, and need for features like multimodality and tool calling.
For a detailed side-by-side comparison, use our comparison tool or check the overall model ranking.
Frequently Asked Questions
What is Claude Sonnet 4.5?
Claude Sonnet 4.5 is Anthropic’s most advanced Sonnet model to date, optimized for real-world agents and coding workflows. It delivers state-of-the-art performance on coding benchmarks such as SWE-bench Verified, with...
How much does Claude Sonnet 4.5 cost?
Claude Sonnet 4.5 costs $3/1M input tokens and $15/1M output tokens. For heavy usage (e.g., a chatbot handling 100k messages/month), costs can range from $10 to $1,000 depending on volume.
How does Claude Sonnet 4.5 compare with other models?
In available benchmarks, Claude Sonnet 4.5 scored: LiveBench Coding: 76.07/100, LiveBench Data Analysis: 47/100, LiveBench Language: 76/100. See the full table above for a detailed comparison.
Is Claude Sonnet 4.5 open source?
No, Claude Sonnet 4.5 is a proprietary model from Anthropic. It is available via cloud API. For open source alternatives, check our open source model ranking.
What is Claude Sonnet 4.5 best for?
Claude Sonnet 4.5 excels at complex reasoning and problem solving. With its large context window, it handles long documents, codebases, and extended conversations. It supports tool calling for API integrations and automation.
Last updated: June 01, 2026 • View methodology →