Gemini 3.1 Pro vs Grok 4.1 Fast
Pricing & Specs
Google (Gemini) vs xAI, side by side from a live registry. Specs below, then benchmark both on your own task.
TL;DR: On a typical task (1K input + 500 output tokens), Grok 4.1 Fast is about 17.8x cheaper than Gemini 3.1 Pro. But per-token price is not cost per result: a cheaper model that needs more tokens, retries, or hand-holding can end up more expensive on your workload. The specs below are facts; which one is better at YOUR task is measurable, not guessable.
API Pricing: Gemini 3.1 Pro vs Grok 4.1 Fast
| Tokens | Gemini 3.1 Pro | Grok 4.1 Fast |
|---|---|---|
| Input | $2 / 1M | $0.2 / 1M |
| Output | $12 / 1M | $0.5 / 1M |
| Cached input | $0.2 / 1M | $0.05 / 1M |
What that means in practice (1K input + 500 output tokens)
Specs Compared
| Spec | Gemini 3.1 Pro | Grok 4.1 Fast |
|---|---|---|
| Context window | 1.04858M tokens | 2M tokens |
| Max output tokens | 65.536K tokens | - |
| Input modalities | text, image, video, audio, PDF | text, image |
| Knowledge cutoff | - | - |
| Latency (measured) | - | ~1.4s median response |
| Reasoning model | Yes | Yes |
| Tool / function calling | Yes | Yes |
| JSON mode | Yes | Yes |
| Prompt caching | Yes | Yes |
When to Choose Which
FAQ
Which is cheaper, Gemini 3.1 Pro or Grok 4.1 Fast?
Gemini 3.1 Pro costs $2/$12 per 1M input/output tokens; Grok 4.1 Fast costs $0.2/$0.5. On a typical task (1K input + 500 output tokens), Grok 4.1 Fast is about 17.8x cheaper than Gemini 3.1 Pro.
Which has the bigger context window, Gemini 3.1 Pro or Grok 4.1 Fast?
Gemini 3.1 Pro has a 1.04858M-token context window; Grok 4.1 Fast has 2M tokens.
Is Gemini 3.1 Pro better than Grok 4.1 Fast?
It depends on the task. Generic leaderboards won't tell you which one wins on YOUR workload. OpenMark lets you benchmark Gemini 3.1 Pro and Grok 4.1 Fast head to head on your own task with real API calls, no API keys needed, free tier available.
Gemini 3.1 Pro or Grok 4.1 Fast for YOUR Task?
Spec tables can't answer that. Run both head to head on your actual workload:
real API calls, ranked results with accuracy, cost, and latency. Free tier available.