Gemini 3.1 Pro: Google's Preview Model With Length-Tiered Pricing
Key facts · verified Nov 3, 2026
Gemini 3.1 Pro is a Google model released on 19 Feb 2026. Its API price is $2 per million input tokens and $12 per million output tokens (prompts <= 200k; $4 / $18 above 200k). Its context window is 1M tokens. It ranks #20 on LMArena's text leaderboard (Elo 1487, read 3 Nov 2026). Source: ai.google.dev.
Google DeepMind's Gemini 3.1 Pro, currently listed by Google as a preview model rather than stable. Pricing is tiered by prompt length: $2 input / $12 output per 1M tokens for prompts up to 200k tokens, rising to $4 / $18 above that.
Key Features
What is Gemini 3.1 Pro?
Gemini 3.1 Pro is a model Google currently lists under Preview rather than its stable line-up - Gemini 3.6 Flash sits in stable by comparison. No dated announcement for it was found, so no release date is given. Google's pricing page does not state a context window for it, so none is quoted here.
On LMArena
On LMArena, a blind head-to-head human-preference leaderboard, Gemini 3.1 Pro has 1487 Elo (rank 20); GPT-5.6 Sol has 1485 Elo (rank 22, xhigh effort) and Claude Opus 5 1492 Elo (rank 14, high effort). Arena measures which answer people prefer, not scientific accuracy.
What Google Does Not Publish
Google's pricing and models pages do not confirm a context window, video understanding, search grounding or Workspace integration for Gemini 3.1 Pro specifically, so this guide does not state them.
Pricing and Access
Google lists Gemini 3.1 Pro at $2 per million input tokens and $12 per million output tokens for prompts up to 200k tokens, and $4 / $18 above that. Developers reach it through Google AI Studio and Vertex AI.
Ranking and Price Against Other Models
On LMArena's text leaderboard Gemini 3.1 Pro has 1487 Elo (rank 20), Claude Opus 5 1492 Elo (rank 14, high effort) and GPT-5.6 Sol 1485 Elo (rank 22, xhigh effort). Published API prices per million input / output tokens, prompts up to 200k: Gemini 3.1 Pro $2 / $12, Claude Opus 5 $5 / $25, GPT-5.6 Sol $4 / $20 (OpenAI's promotional price).
Key Takeaways
- Listed by Google as a preview model, not part of the stable line-up
- LMArena: 1487 Elo (rank 20)
- No context window figure is published by Google, so none is claimed here
- Pricing: $2/$12 per million tokens for prompts up to 200k, $4/$18 above that
- Input price $2 per million tokens, against $5 for Claude Opus 5 and $4 for GPT-5.6 Sol
Official Resources
Full Specifications
$2 / $12 per million tokens | |
|---|---|
| Identity | |
| Developer | |
| Released | Feb 2026 |
| Status | Preview |
| Licence | Proprietary |
| Self-hostable | No |
| Cost | |
| Blended $/1M tokensinput × 0.75 + output × 0.25 | $4.500 / 1M tokens |
| Input price | $2.000 / 1M tokens |
| Output price | $12.000 / 1M tokens |
| Cached input | $0.20 / 1M tokens (cache hit, <=200k tier) |
| Batch discount | 50% off input/output (Batch API) |
| Free tier | Not offered |
| Capacity | |
| Context window | 1M tokens |
| Max output | 64k tokens |
| Long-context surcharge | 2x input / 1.5x output above 200k prompt tokens |
| Capability | |
| Vision in | Yes |
| Audio in | Yes |
| Function calling | Yes |
| Structured output | Yes |
| Extended reasoning | Yes |
| Web search | Yes |
| Code execution | Yes |
| Access | |
| API | Yes |
| Chat app | Yes |
| Cloud marketplaces | Not offered |
| Fine-tuning | Not offered |
| Measured quality | |
| LMArena Elo | 1487 (checked Nov 2026) |
| LMArena rank | Rank 20 |
| Elo per dollarLMArena Elo ÷ blended $/1M tokens | 330 |