Claude Sonnet 4.5 vs Gemini 3.1 Pro
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 Sonnet 4.5 and Gemini 3.1 Pro.
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...
Gemini 3.1 Pro
Google's premiere multi-modal model featuring a massive 2 million token context window. Engineered for deep code analysis, video indexing, and long-context reasoning.
Technical Specifications
| Specification | Claude Sonnet 4.5 | Gemini 3.1 Pro |
|---|---|---|
| Provider | Anthropic | |
| Context Window | 1,000,000 tokens | 2,000,000 tokens |
| Agent Suitability | 91/100 | 93/100 |
| Time to First Token (TTFT) | 380 ms | 420 ms |
| Deployment Model | managed api | managed api |
| Production Stability | stable | stable |
| API Available | Yes | Yes |
| Released Date | 2025-09-29 | 2026-04-20 |
API Pricing Comparison
Input Price per Million Tokens
Claude Sonnet 4.5
$3.00
Gemini 3.1 Pro
$2.00
Output Price per Million Tokens
Claude Sonnet 4.5
$15.00
Gemini 3.1 Pro
$12.00
Want to test both models live?
Run side-by-side prompt prompts in our dynamic Sandbox. Check execution speeds, latency metrics, and compute actual costs in real-time.
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 Sonnet 4.5 Quirks & Gotchas
- ▸Excellent for long-form writing and nuanced document analysis
- ▸Slightly slower than Sonnet 4.6 — upgrade for production agentic use
Gemini 3.1 Pro Quirks & Gotchas
- ▸Best model for massive context — 2M token window is class-leading
- ▸Tool calling requires explicit schema definition in Google AI Studio