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.
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[*] |
Input token limit 1,048,576 Output token limit 65,536 |
| Capabilities |
Audio generation Not supported Batch API Supported Caching Supported Code execution Supported File search Supported (AI Studio only) Function calling Supported Grounding with Google Maps Not supported Image generation Not supported Live API Not supported Search grounding Supported Structured outputs Supported Thinking Supported URL context Supported |
| Versions |
|
| Latest update | February 2026 |
| Knowledge cutoff | January 2025 |
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.