Gemini 3.1 Pro Preview Custom Tools API Cost Calculator
Estimate your monthly API costs for Gemini 3.1 Pro Preview Custom Tools from Google.
Pricing per 1M tokens
Pricing last verified: Mar 21, 2026
30-Day Price History
Solid line: input price · Dashed line: output price
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Cost Breakdown
Compare with Similar Models
| Model | Input/1M | Output/1M |
|---|---|---|
| Nano Banana Pro (Gemini 3 Pro Image Preview) Google | $2.00 | $12.00 |
| Gemini 3 Pro Preview Google | $2.00 | $12.00 |
| Gemini 3.1 Pro Preview Google | $2.00 | $12.00 |
| Gemini 2.5 Pro Preview 06-05 Google | $1.25 | $10.00 |
| Gemini 2.5 Pro Preview 05-06 Google | $1.25 | $10.00 |
Frequently Asked Questions
How much does Gemini 3.1 Pro Preview Custom Tools cost per token?
Gemini 3.1 Pro Preview Custom Tools is priced at $2.00 per 1M input tokens and $12.00 per 1M output tokens. Use the calculator above to estimate your monthly costs based on your usage volume.
What is the context window for Gemini 3.1 Pro Preview Custom Tools?
Gemini 3.1 Pro Preview Custom Tools has a context window of 1.0M tokens (1,048,576 tokens). The maximum output length is 65.5K tokens.
Does Gemini 3.1 Pro Preview Custom Tools support image inputs (vision)?
Yes, Gemini 3.1 Pro Preview Custom Tools supports vision/image inputs. You can send images as part of your prompts.
Does Gemini 3.1 Pro Preview Custom Tools support function calling (tool use)?
Yes, Gemini 3.1 Pro Preview Custom Tools supports function calling (also called tool use). You can define custom functions that the model can invoke as part of its responses.
How does Gemini 3.1 Pro Preview Custom Tools compare to similar models?
Gemini 3.1 Pro Preview Custom Tools costs $2.00 input and $12.00 output per 1M tokens. Gemini 2.5 Pro Preview 05-06 is less expensive at $1.25 input and $10.00 output per 1M tokens. See the "Compare with Similar Models" table above, or visit the Gemini 2.5 Pro Preview 05-06 page at /tools/cost-calculator/google/gemini-2-5-pro-preview-05-06.