Gemini 3.1 Pro Preview Custom Tools
$2.00 per 1M input tokens and $12.00 per 1M output tokens · 1.05M context · vision, audio, tools, reasoning, JSON.
Prices checked Oct 21, 2026 · tracked by LLM Cost Index since Oct 21, 2026
What Gemini 3.1 Pro Preview Custom Tools costs per month
Estimated monthly bill for typical workloads, using the cached-input price for repeated context. Try your own numbers in the cost calculator.
| Workload | Per month |
|---|---|
| Customer chatbot 1,000 conversations a day, 8 turns each | $1,339 |
| Document Q&A (RAG) 500 questions a day over retrieved documents | $254 |
| Coding / tool-using agent 200 tasks a day, long tool-heavy contexts | $522 |
| Content generation 30 long articles a day | $32.40 |
| Classification / extraction 100,000 short items a day | $2,340 |
Prompts above 200K tokens are billed at $4.00 input / $18.00 output per 1M.
Price history
We started tracking Gemini 3.1 Pro Preview Custom Tools on Oct 21, 2026; the chart appears as soon as there is a second data point. See all recent price changes.
Cheaper alternatives to Gemini 3.1 Pro Preview Custom Tools
Models with the same tool calling, image input, structured output for at least 20% less (3:1 input/output mix), most capable first.
| Model | Input / 1M | Output / 1M | Context | Capabilities |
|---|---|---|---|---|
| Muse Spark 1.3 Meta | $1.25 | $4.25 | 1.05M | visiontoolsreasoningJSON |
| Grok 4.7 xAI | $2.00 | $6.00 | 500K | visiontoolsreasoningJSON |
| MiMo-V2.6-Pro Xiaomi | $0.435 | $0.87 | 1.05M | visionaudiotoolsreasoningJSONopen weights |
| $2.00 | $6.00 | 1M | visiontoolsreasoningJSON | |
| Grok 4.6 xAI | $2.00 | $6.00 | 500K | visiontoolsreasoningJSON |
How to pay less for Gemini 3.1 Pro Preview Custom Tools
For a customer chatbot (1,000 conversations a day, 8 turns each) that costs $1,728 a month at list price without caching:
| Option | Per month | You save |
|---|---|---|
| Move to Muse Spark 1.3 (similar capabilities) | $569 | $1,159 (67%) |
| Use prompt caching (60% of input cached) | $1,339 | $389 (22%) |
Other workloads: cut-your-bill tool for Gemini 3.1 Pro Preview Custom Tools.
Specifications
| Model ID | google/gemini-3.1-pro-preview-customtools |
| Input | text, audio, image, video, file |
| Output | text |
| Tool calling | Yes |
| Structured output | Yes |
| Reasoning mode | Yes |
| Open weights | No |
| Released | Feb 25, 2026 |
| Web search | $0.014 per request |
FAQ
- How much does Gemini 3.1 Pro Preview Custom Tools cost?
- $2.00 per million input tokens and $12.00 per million output tokens; cached input costs $0.20 per million. Prompts over 200K tokens are billed at $4.00 / $18.00. Prices as of Oct 21, 2026.
- What is the context window of Gemini 3.1 Pro Preview Custom Tools?
- 1.05M tokens, with up to 66K output tokens per response.
- Does Gemini 3.1 Pro Preview Custom Tools support images, tools and structured output?
- Images as input: yes. Tool calling: yes. Structured (JSON) output: yes. Reasoning mode: yes.
- What are cheaper alternatives to Gemini 3.1 Pro Preview Custom Tools?
- Models with the same key capabilities for at least 20% less include Muse Spark 1.3 ($1.25 / $4.25), Grok 4.7 ($2.00 / $6.00), MiMo-V2.6-Pro ($0.435 / $0.87).
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