Claude 3.5 Sonnet vs Claude Opus 4.5
How do these models stack up? Below is an expert side-by-side comparison of specifications, context window capacity, live pricing per million tokens, and standardized benchmark scores for Claude 3.5 Sonnet and Claude Opus 4.5.
Claude 3.5 Sonnet
Claude 3.5 Sonnet was Anthropic's breakout model of 2024, widely regarded as one of the most capable commercial LLMs of its generation. It earned widespread developer praise for its exceptional coding ability, nuanced long-form writing, and reliable complex reasoning across a 200,000-token context window. Claude 3.5 Sonnet introduced computer-use capabilities, enabling it to interact with desktop environments, web browsers, and software tools autonomously. Available via API at $3/MTok for input, it continues to be a popular choice for developers who want a well-rounded, safety-aligned model with strong benchmark performance for coding, analysis, and content generation tasks.
Claude Opus 4.5
Claude Opus 4.5 is Anthropic’s frontier reasoning model optimized for complex software engineering, agentic workflows, and long-horizon computer use. It offers strong multimodal capabilities, competitive performance across real-world coding and...
Technical Specifications
| Specification | Claude 3.5 Sonnet | Claude Opus 4.5 |
|---|---|---|
| Provider | Anthropic | Anthropic |
| Context Window | 200,000 tokens | 200,000 tokens |
| Agent Suitability | N/A | 93/100 |
| Time to First Token (TTFT) | N/A | 550 ms |
| Deployment Model | N/A | managed api |
| Production Stability | stable | stable |
| API Available | Yes | Yes |
| Released Date | 2024-06-21 | 2025-11-24 |
API Pricing Comparison
Input Price per Million Tokens
Claude 3.5 Sonnet
$3.00
Claude Opus 4.5
$5.00
Output Price per Million Tokens
Claude 3.5 Sonnet
$15.00
Claude Opus 4.5
$25.00
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Benchmark Performance Metrics
Scores show the raw performance percentages verified across key evaluation suites. Higher bars indicate superior accuracy and capability in that domain.
Claude 3.5 Sonnet Quirks & Gotchas
No developer gotchas reported.
Claude Opus 4.5 Quirks & Gotchas
- ▸Deep analytical reasoning — best for structured problem-solving
- ▸200K context is limiting compared to 1M of Opus 4.6+ — upgrade for long-document tasks