Gemini 3.1 Pro Preview is Google’s frontier reasoning model, delivering enhanced software engineering performance, improved agentic reliability, and more efficient token usage across complex workflows. Building on the multimodal foundation.…
Model details →Google: Gemini 3.1 Pro Preview vs OpenAI: GPT-5.6 Luna Pro
OpenAI: GPT-5.6 Luna Pro wins on 3 of 6 axes — pricing and capability skew in its favour for most workloads.
GPT-5.6 Luna Pro is the same underlying model as [GPT-5.6 Luna](https://openrouter.ai/openai/gpt-5.6-luna), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks. Learn more in OpenAI's docs: https://devel…
Model details →Side-by-side comparison
| Capability | Google: Gemini 3.1 Pro Preview | OpenAI: GPT-5.6 Luna Pro | Winner |
|---|---|---|---|
| Context window Maximum number of input tokens the model can attend to in a single request. | 1.0M | 1.1M | 🏆 OpenAI: GPT-5.6 Luna Pro |
| Input price (per 1M) Cost per million input tokens billed by the provider. | $2.00 | $0.10 | 🏆 OpenAI: GPT-5.6 Luna Pro |
| Output price (per 1M) Cost per million output tokens billed by the provider. | $12.00 | $0.60 | 🏆 OpenAI: GPT-5.6 Luna Pro |
| Tool / function calling First-class support for emitting structured tool calls. | Yes | Yes | Tie |
| Vision input Accepts image inputs alongside text. | Yes | Yes | Tie |
| Reasoning mode Internal chain-of-thought / extended-thinking support. | Yes | Yes | Tie |
Frequently asked questions
Is Google: Gemini 3.1 Pro Preview better than OpenAI: GPT-5.6 Luna Pro?
OpenAI: GPT-5.6 Luna Pro wins on 3 of 6 axes — pricing and capability skew in its favour for most workloads.
What's the price difference between Google: Gemini 3.1 Pro Preview and OpenAI: GPT-5.6 Luna Pro?
Input: $2.00 vs $0.10 per 1M tokens. Output: $12.00 vs $0.60 per 1M tokens.
What context windows do Google: Gemini 3.1 Pro Preview and OpenAI: GPT-5.6 Luna Pro support?
Google: Gemini 3.1 Pro Preview supports up to 1.0M tokens. OpenAI: GPT-5.6 Luna Pro supports up to 1.1M tokens.
Do both Google: Gemini 3.1 Pro Preview and OpenAI: GPT-5.6 Luna Pro support tool calling?
Google: Gemini 3.1 Pro Preview: yes. OpenAI: GPT-5.6 Luna Pro: yes.
Compare Google: Gemini 3.1 Pro Preview with other models
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