Claude Sonnet 4.5 vs Gemini 3.1 Pro Preview
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 Preview.
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 Preview
Gemini 3.1 Pro Preview is Google’s frontier reasoning model, delivering enhanced software engineering performance, improved agentic reliability, and more efficient token usage across complex workflows. Building on the multimodal foundation...
Technical Specifications
| Specification | Claude Sonnet 4.5 | Gemini 3.1 Pro Preview |
|---|---|---|
| Provider | Anthropic | |
| Context Window | 1,000,000 tokens | 1,048,576 tokens |
| Agent Suitability | 91/100 | N/A |
| Time to First Token (TTFT) | 380 ms | N/A |
| Deployment Model | managed api | managed api |
| Production Stability | stable | beta |
| API Available | Yes | Yes |
| Released Date | 2025-09-29 | 2026-02-19 |
API Pricing Comparison
Input Price per Million Tokens
Claude Sonnet 4.5
$3.00
Gemini 3.1 Pro Preview
$2.00
Output Price per Million Tokens
Claude Sonnet 4.5
$15.00
Gemini 3.1 Pro Preview
$12.00
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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 Preview Quirks & Gotchas
No developer gotchas reported.