Gemini 3 Pro Preview vs Grok 4
Data reconciled September 29, 2026
Short answer
Gemini 3 Pro Preview and Grok 4 each win on different axes — neither is simply cheaper or better across the board.
Grok 4 is 1.6× cheaper on input.
Grok 4 is 4.8× cheaper on output.
Gemini 3 Pro Preview holds a 4.1× larger context window.
Grok 4 returns a 3.9× longer answer per call.
Image input is supported only by Gemini 3 Pro Preview.
Reasoning mode is supported only by Gemini 3 Pro Preview.
Side by side
| Parameter | Gemini 3 Pro Preview | Grok 4 |
|---|---|---|
| Provider | Google (Gemini) | xAI |
| Input, $ per 1M tokens | $2.00 | $1.25 |
| Output, $ per 1M tokens | $12.00 | $2.50 |
| Cache read, $ per 1M | $0.20 | $0.20 |
| Context window | 1,048,576 | 256,000 |
| Max output | 65,535 | 256,000 |
| Vision | yes | no |
| Tools | yes | yes |
| Reasoning | yes | no |
| Status | available | available |
What it costs on your own workload
A price gap per million tokens says little until your volumes are plugged in: on a long fixed system prompt the winner is the model with cheap cache reads, not the one with a cheap input rate. Run Gemini 3 Pro Preview and Grok 4 against your own numbers.
Open the cost calculatorWhat is deliberately absent
We do not compare answer quality and we do not reprint third-party benchmarks. We have no quality measurements of our own, and external tables go stale faster than prices while being compiled, almost always, by someone with a stake in the result. What is here is only what we reconcile ourselves every day: prices, limits and supported capabilities.