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 or user-defined functions are available. This specialized …
Model details →Google: Gemini 3.1 Pro Preview Custom Tools vs OpenAI: GPT-5 Pro
Google: Gemini 3.1 Pro Preview Custom Tools wins on 3 of 6 axes — pricing and capability skew in its favour for most workloads.
GPT-5 Pro is OpenAI’s most advanced model, offering major improvements in reasoning, code quality, and user experience. It is optimized for complex tasks that require step-by-step reasoning, instruction following, and accuracy in high-stake…
Model details →Side-by-side comparison
| Capability | Google: Gemini 3.1 Pro Preview Custom Tools | OpenAI: GPT-5 Pro | Winner |
|---|---|---|---|
| Context window Maximum number of input tokens the model can attend to in a single request. | 1.0M | 400K | 🏆 Google: Gemini 3.1 Pro Preview Custom Tools |
| Input price (per 1M) Cost per million input tokens billed by the provider. | $2.00 | $15.00 | 🏆 Google: Gemini 3.1 Pro Preview Custom Tools |
| Output price (per 1M) Cost per million output tokens billed by the provider. | $12.00 | $120.00 | 🏆 Google: Gemini 3.1 Pro Preview Custom Tools |
| Tool / function calling First-class support for emitting structured tool calls. | Yes | Yes | Tie |
| Vision input Accepts image inputs alongside text. | Yes | Yes | Tie |
| Reasoning mode Internal chain-of-thought / extended-thinking support. | Yes | Yes | Tie |
Frequently asked questions
Is Google: Gemini 3.1 Pro Preview Custom Tools better than OpenAI: GPT-5 Pro?
Google: Gemini 3.1 Pro Preview Custom Tools wins on 3 of 6 axes — pricing and capability skew in its favour for most workloads.
What's the price difference between Google: Gemini 3.1 Pro Preview Custom Tools and OpenAI: GPT-5 Pro?
Input: $2.00 vs $15.00 per 1M tokens. Output: $12.00 vs $120.00 per 1M tokens.
What context windows do Google: Gemini 3.1 Pro Preview Custom Tools and OpenAI: GPT-5 Pro support?
Google: Gemini 3.1 Pro Preview Custom Tools supports up to 1.0M tokens. OpenAI: GPT-5 Pro supports up to 400K tokens.
Do both Google: Gemini 3.1 Pro Preview Custom Tools and OpenAI: GPT-5 Pro support tool calling?
Google: Gemini 3.1 Pro Preview Custom Tools: yes. OpenAI: GPT-5 Pro: yes.