Gemini 3.1 Pro Preview Custom Tools vs GPT-5.5
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 Gemini 3.1 Pro Preview Custom Tools and GPT-5.5.
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...
GPT-5.5
GPT-5.5 is OpenAI’s frontier model designed for complex professional workloads, building on GPT-5.4 with stronger reasoning, higher reliability, and improved token efficiency on hard tasks. It features a 1M+ token...
Technical Specifications
| Specification | Gemini 3.1 Pro Preview Custom Tools | GPT-5.5 |
|---|---|---|
| Provider | OpenAI | |
| Context Window | 1,048,756 tokens | 1,050,000 tokens |
| Agent Suitability | N/A | 95/100 |
| Time to First Token (TTFT) | N/A | 380 ms |
| Deployment Model | managed api | managed api |
| Production Stability | beta | stable |
| API Available | Yes | Yes |
| Released Date | 2026-02-25 | 2026-04-24 |
API Pricing Comparison
Input Price per Million Tokens
Gemini 3.1 Pro Preview Custom Tools
$2.00
GPT-5.5
$5.00
Output Price per Million Tokens
Gemini 3.1 Pro Preview Custom Tools
$12.00
GPT-5.5
$30.00
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.
Gemini 3.1 Pro Preview Custom Tools Quirks & Gotchas
No developer gotchas reported.
GPT-5.5 Quirks & Gotchas
- ▸Best for JSON schema adherence — strict mode available via response_format parameter
- ▸Requires explicit tool_choice for deterministic function calling