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 xAI: Grok 4 Fast
xAI: Grok 4 Fast wins on 3 of 6 axes — pricing and capability skew in its favour for most workloads.
Grok 4 Fast is xAI's latest multimodal model with SOTA cost-efficiency and a 2M token context window. It comes in two flavors: non-reasoning and reasoning. Read more about the model on xAI's [news post](http://x.ai/news/grok-4-fast). Reaso…
Model details →Side-by-side comparison
| Capability | Google: Gemini 3.1 Pro Preview | xAI: Grok 4 Fast | Winner |
|---|---|---|---|
| Context window Maximum number of input tokens the model can attend to in a single request. | 1.0M | 2M | 🏆 xAI: Grok 4 Fast |
| Input price (per 1M) Cost per million input tokens billed by the provider. | $2.00 | $0.20 | 🏆 xAI: Grok 4 Fast |
| Output price (per 1M) Cost per million output tokens billed by the provider. | $12.00 | $0.50 | 🏆 xAI: Grok 4 Fast |
| 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 xAI: Grok 4 Fast?
xAI: Grok 4 Fast 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 xAI: Grok 4 Fast?
Input: $2.00 vs $0.20 per 1M tokens. Output: $12.00 vs $0.50 per 1M tokens.
What context windows do Google: Gemini 3.1 Pro Preview and xAI: Grok 4 Fast support?
Google: Gemini 3.1 Pro Preview supports up to 1.0M tokens. xAI: Grok 4 Fast supports up to 2M tokens.
Do both Google: Gemini 3.1 Pro Preview and xAI: Grok 4 Fast support tool calling?
Google: Gemini 3.1 Pro Preview: yes. xAI: Grok 4 Fast: yes.