Gemini 3.1 Pro
Google's shipping flagship while 3.5 Pro remains unreleased, and the cheapest frontier model by a wide margin. It still tops several hard-reasoning boards including GPQA Diamond and ARC-AGI-2, making it the value choice for research-style workloads — provided you keep prompts under 200K tokens, where the price doubles.
Pricing checked against provider documentation on . How we verify
gemini-3.1-pro-preview reasoning Input
$2.00
/ 1M tokens
Output
$12.00
/ 1M tokens
Context
1.05M
1,048,576 tokens
Max output
66K
tokens per request
Pricing caveat: Prompts over 200K tokens reprice to $4 input / $18 output per 1M.
What it costs in practice
A workload of 10M input and 2M output tokens per month — roughly a moderately busy production assistant — runs $44.00/month on Gemini 3.1 Pro. Routing that same volume through the batch API brings it to $22.00. The next cheaper option, Claude Sonnet 5 , would cost $40.00.
Where Gemini 3.1 Pro fits
- Hard reasoning and research tasks
- Long-context document and video analysis
- Native multimodal pipelines
- Cost-conscious frontier workloads
Published benchmarks
| Benchmark | Score |
|---|---|
| GPQA Diamond | 94.6% |
Scores are self-reported by providers or drawn from independent indices. Treat them as directional and validate on your own evals.
Specifications
- API model ID
- gemini-3.1-pro-preview
- Provider
- Model family
- Gemini 3.1
- Released
- March 2026
- Knowledge cutoff
- June 2025
- Context window
- 1,048,576 tokens
- Max output
- 65,536 tokens
- Native reasoning
- Yes
- Relative latency
- medium
- Input modalities
- text, image, audio, video, pdf
- Output modalities
- text
- Open weights
- No
- Cached input
- —
- Batch discount
- 50%
Frequently asked
How much does Gemini 3.1 Pro cost?
Gemini 3.1 Pro costs $2.00 per million input tokens and $12.00 per million output tokens. Batch processing is 50% cheaper.
What is Gemini 3.1 Pro's context window?
Gemini 3.1 Pro accepts up to 1,048,576 tokens of context and can generate up to 65,536 output tokens per request.
Is Gemini 3.1 Pro a reasoning model?
Yes. Gemini 3.1 Pro performs native chain-of-thought before answering. Those thinking tokens are billed at the output rate, so budget above the sticker price.
What is Gemini 3.1 Pro best for?
Best price-to-reasoning ratio. Google's shipping flagship while 3.5 Pro remains unreleased, and the cheapest frontier model by a wide margin. It still tops several hard-reasoning boards including GPQA Diamond and ARC-AGI-2, making it the value choice for research-style workloads — provided you keep prompts under 200K tokens, where the price doubles.