Gemini 3.1 Pro vs Gemini 3.1 Pro Preview Custom Tools
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 Gemini 3.1 Pro and Gemini 3.1 Pro Preview Custom Tools.
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.
Gemini 3.1 Pro Preview Custom Tools
Gemini 3.1 Pro Preview Custom Tools is a variant of Gemini 3.1 Pro that improves tool selection behavior by preventing overuse of a general bash tool when more efficient third-party...
Technical Specifications
| Specification | Gemini 3.1 Pro | Gemini 3.1 Pro Preview Custom Tools |
|---|---|---|
| Provider | ||
| Context Window | 2,000,000 tokens | 1,048,756 tokens |
| Agent Suitability | 93/100 | N/A |
| Time to First Token (TTFT) | 420 ms | N/A |
| Deployment Model | managed api | managed api |
| Production Stability | stable | beta |
| API Available | Yes | Yes |
| Released Date | 2026-04-20 | 2026-02-25 |
API Pricing Comparison
Input Price per Million Tokens
Gemini 3.1 Pro
$2.00
Gemini 3.1 Pro Preview Custom Tools
$2.00
Output Price per Million Tokens
Gemini 3.1 Pro
$12.00
Gemini 3.1 Pro Preview Custom Tools
$12.00
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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.
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
Gemini 3.1 Pro Preview Custom Tools Quirks & Gotchas
No developer gotchas reported.