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 |
Not supported Supported Supported Supported (AI Studio only) Supported Supported Not supported Not supported Supported Supported Supported Supported |
| Consumption options |
Supported Supported 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.