Built to refine the performance and reliability of the Gemini 3 Pro series, Gemini 3.1 Pro Preview provides better thinking, improved token efficiency, and a more grounded, factually consistent experience. It's optimized for software engineering behavior and usability, as well as agentic workflows requiring precise tool usage and reliable multi-step execution across real-world domains. Try in Google AI Studio
Documentation
Visit the Gemini 3 Developer Guide page for full coverage of features and capabilities.
gemini-3.1-pro-preview
| Property | Description |
|---|---|
| Model code | gemini-3.1-pro-preview |
| Supported data types | Inputs Text, Image, Video, Audio, and PDF Output Text |
| Token limits[1](https://ai.google.dev/gemini-api/docs/tokens)^ | Input token limit 1,048,576 Output token limit 65,536 |
| Capabilities | Audio generation Not supported Caching Supported Code execution Supported File search Supported (AI Studio only) Function calling Supported Grounding with Google Maps Supported Image generation Not supported Live API Not supported Search grounding Supported Structured outputs Supported Thinking Supported URL context Supported |
| Consumption options | Batch API Supported Flex inference Supported Priority inference Supported |
| Versions | Read the model version patterns for more details. - Preview: gemini-3.1-pro-preview - Preview: gemini-3.1-pro-preview-customtools * |
| Latest update | February 2026 |
| Model card | Model card |
gemini-3.1-pro-preview-customtools
* For those building with a mix of bash and custom tools, Gemini 3.1 Pro Preview
comes with a separate endpoint available via the API called
gemini-3.1-pro-preview-customtools. This endpoint is better at prioritizing
your custom tools (for example view_file or search_code).
Note that while gemini-3.1-pro-preview-customtools is optimized for agentic
workflows that use custom tools and bash, you may see quality fluctuations in
some use cases which don't benefit from such tools.
[*] ↩︎