Gemini 3.1 Pro Preview Custom Tools API Pricing
Google · Mid-tier · Proprietary · released 2026-02. Prices in USD per 1 million tokens. Data snapshot: 2026-09-06.
- Input: $2.00 per 1M tokens
- Output: $12.00 per 1M tokens
- Batch API (input/output): not published
- Prompt-cache read: $0.20
- Context window: 1M
Cost per request by business use case
List price vs optimized (prompt caching on the cached input share, batch API for async workloads, only where the provider publishes those rates).
| Use case | Tokens (in/out) | Cost/req (list) | Cost/req (optimized) | Monthly @100K req |
|---|---|---|---|---|
| Support Ticket | 1,500 / 500 | $0.0090 | $0.0074 | $738 |
| Knowledge Q&A | 2,000 / 800 | $0.014 | $0.011 | $1.1K |
| Meeting Summary | 10,000 / 1,200 | $0.034 | $0.033 | $3.3K |
| Marketing Content | 2,500 / 1,800 | $0.027 | $0.026 | $2.6K |
| Coding Task | 3,000 / 2,000 | $0.030 | $0.027 | $2.7K |
| Invoice Processing | 1,500 / 600 | $0.010 | $0.0094 | $939 |
| Call Summary | 2,000 / 700 | $0.012 | $0.012 | $1.2K |
| Agent Workflow | 6,000 / 3,000 | $0.048 | $0.040 | $4.0K |
Gemini 3.1 Pro Preview Custom Tools pricing by host
A host is a company that runs the model and sells it by the token — the lab that made it, a cloud platform like Amazon Bedrock, Azure or Vertex, or an independent provider. One model, several sellers, and often several prices. This model is sold by 1 host. The price quoted above is the one we publish so that models stay comparable; it is not necessarily the cheapest way to buy this model. List prices as published on 2026-09-06 via OpenRouter — negotiated rates, committed-use discounts and provisioned capacity are not shown.
| Host | Input $/1M | Output $/1M |
|---|---|---|
| Google AI Studio (the price shown above) | $2.00 | $12.00 |
Common questions about Gemini 3.1 Pro Preview Custom Tools pricing
- How much does Gemini 3.1 Pro Preview Custom Tools cost?
- Gemini 3.1 Pro Preview Custom Tools costs $2.00 per million input tokens and $12.00 per million output tokens on the API.
- Does Gemini 3.1 Pro Preview Custom Tools offer batch or cached pricing?
- Prompt-cache reads cost $0.20/M input tokens. No batch pricing is published.
- What would Gemini 3.1 Pro Preview Custom Tools cost per month?
- For a support-ticket workload (1,500 input + 500 output tokens per request) at 100K requests/month, Gemini 3.1 Pro Preview Custom Tools costs about $900 at list prices.
These are list prices: real cost also depends on caching, batching, negotiated discounts, marketplace agreements, and existing contracts. Get a FinOps review from OptimNow or compare all models.
Build the business case for Gemini 3.1 Pro Preview Custom Tools in the AI ROI Calculator: add your business value on top of these costs to get ROI, break-even and payback.
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