Gemini 3.1 Pro
Gemini 3.1 Pro is Google's newest Pro-tier Gemini model and is still offered as a preview. Launched on February 19, 2026, it handles text, images, video, audio and PDFs, and Google says it is tuned for software engineering behavior and usability.
Specifications
- Context window
- 1Mabout 786,000 words, or 1,570 pages
- Max output
- 64Ktokens per response
- Input price
- $2per 1M tokens
- Output price
- $12per 1M tokens
- Cached input
- $0.20per 1M tokens
- Weights
- ClosedProprietary
- Parameters
- Undisclosed
- Input types
- Text, Images, Video, Audio, PDF
- Output types
- Text
- Reasoning mode
- Yes
- Tool calling
- Yes
- Released
- Feb 19, 2026Preview
Paid-tier rates for prompts up to 200K tokens; a larger prompt costs $4 input, $18 output and $0.40 caching. No free tier. Batch and Flex 50% off; Priority costs more. Cache storage $4.50 per 1M tokens per hour.
What it costs in practice
| Workload | Monthly cost at list price |
|---|---|
| Support chatbot30,000 conversations a month, 2,000 input and 400 output tokens each | $264 |
| Document summaries2,000 documents a month, 12,000 input and 800 output tokens each | $67 |
| Coding agent1,000 tasks a month, 60,000 input and 6,000 output tokens each | $192 |
Standard rates, no caching or batch discounts. Run your own numbers.
Strengths
- 1,048,576-token input limit and 65,536-token output limit
- Accepts text, image, video, audio and PDF input
- Supports search grounding, code execution and URL context
Trade-offs to weigh
- Still a preview model, with no stable version listed as of October 2026
- No free tier, and prompts over 200K tokens cost more
Where it fits
Google positions Gemini 3.1 Pro for:
Where you can use it
- API
- Google Vertex AI
Alternatives to consider
| Model | Tier | Context | Input / output per 1M | |
|---|---|---|---|---|
| Grok 4.7xAI | Frontier | 500K | $2 / $6 | Compare |
| Qwen3.8-MaxAlibaba (Qwen) | Frontier | 1M | $2 / $6 | Compare |
| Claude Opus 5.5Anthropic | Frontier | 1M | $4 / $20 | Compare |
| Kimi K3Moonshot AI | Frontier | 1M | $3 / $15 | Compare |
Frequently asked questions
How much does Gemini 3.1 Pro cost?
Gemini 3.1 Pro lists at $2 per million input tokens and $12 per million output tokens, with cached input at $0.20 (checked October 10, 2026). Paid-tier rates for prompts up to 200K tokens; a larger prompt costs $4 input, $18 output and $0.40 caching. No free tier. Batch and Flex 50% off; Priority costs more. Cache storage $4.50 per 1M tokens per hour. Confirm current rates on the provider's pricing page before you commit.
What is the context window of Gemini 3.1 Pro?
Gemini 3.1 Pro accepts up to 1,048,576 tokens of context (about 786,000 words, or 1,570 pages), and it can write up to 64K tokens in a single response. Long prompts cost more and can be slower, so most apps send only what the task needs.
Is Gemini 3.1 Pro open source?
No. Gemini 3.1 Pro is a proprietary model from Google; its weights aren't published. You can use it through the Google API and through Google Vertex AI.
What is Gemini 3.1 Pro best for?
Google positions Gemini 3.1 Pro for reasoning, coding, multimodal, long documents. It accepts text, images, video, audio, pdf as input, has a reasoning (thinking) mode and supports tool calling. Test it on a sample of your own tasks before you choose it for production.
Sources
- ai.google.dev/gemini-api/docs/models/gemini-3.1-pro-preview
- ai.google.dev/gemini-api/docs/pricing
- ai.google.dev/gemini-api/docs/models
- ai.google.dev/gemini-api/docs/changelog
- docs.perplexity.ai/docs/agent-api/models.md
Facts checked against these pages on October 10, 2026. Spot an error? Tell us.
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