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Gemini 3.1 Pro vs Grok 4.1 Fast

Pricing, context window, and benchmark comparison · Last updated April 2026

Quick Verdict

Grok 4.1 Fast is cheaper than Gemini 3.1 Pro at $0.20/1M/1M vs $2.00/1M/1M input tokens — a 10.0x cost difference. Gemini 3.1 Pro scores higher on quality benchmarks (ELO 1410). Choose Grok 4.1 Fast for cost-sensitive workloads; choose Gemini 3.1 Pro for maximum quality.

Detailed Comparison

MetricGemini 3.1 ProGrok 4.1 Fast
Input Price / 1M tokens$2.00/1M$0.20/1MCheaper
Output Price / 1M tokens$12.00/1M$0.50/1MCheaper
Context Window1M2MLarger
ELO Score (LMSYS)1410Smarter1305
Open Source
Free Tier
Release Date2026-032026-01

Which is cheaper: Gemini 3.1 Pro or Grok 4.1 Fast?

Grok 4.1 Fast is the cheaper option at $0.20/1M per 1M input tokens, compared to $2.00/1M for Gemini 3.1 Pro. That is a 10.0x cost difference on input tokens. Output pricing follows a similar pattern: Gemini 3.1 Pro charges $12.00/1M/1M vs $0.50/1M/1M for Grok 4.1 Fast.

Which has better quality: Gemini 3.1 Pro or Grok 4.1 Fast?

Based on LMSYS Chatbot Arena rankings, Gemini 3.1 Pro achieves a higher ELO score (1410 vs 1305), suggesting stronger performance on open-ended tasks. Gemini 3.1 Pro excels at google's latest flagship with major reasoning improvements. Grok 4.1 Fast is known for 2m token context at $0.20/$0.50 per 1m — unbeatable for long context.

Which should you choose: Gemini 3.1 Pro or Grok 4.1 Fast?

Choose Gemini 3.1 Pro if:
  • Google's latest flagship with major reasoning improvements
  • 1M token context window
  • Native multimodal (text, image, video, audio)
Choose Grok 4.1 Fast if:
  • 2M token context at $0.20/$0.50 per 1M — unbeatable for long context
  • Very fast inference
  • Real-time X data access

Frequently Asked Questions

Which is cheaper: Gemini 3.1 Pro or Grok 4.1 Fast?

Grok 4.1 Fast is cheaper at $0.20/1M per 1M input tokens, making it 10.0x more affordable.

Which has better quality: Gemini 3.1 Pro or Grok 4.1 Fast?

Gemini 3.1 Pro scores higher on the LMSYS Chatbot Arena with an ELO of 1410, suggesting better overall quality for most tasks.

Which has a larger context window: Gemini 3.1 Pro or Grok 4.1 Fast?

Grok 4.1 Fast has a larger context window at 2000K tokens.

Should I choose Gemini 3.1 Pro or Grok 4.1 Fast?

Choose Grok 4.1 Fast if cost is the priority. Choose Gemini 3.1 Pro if benchmark quality is most important. Consider your specific use case: Gemini 3.1 Pro is best for reasoning and long-context, while Grok 4.1 Fast excels at long-context and low-cost.

Is Gemini 3.1 Pro or Grok 4.1 Fast open source?

Gemini 3.1 Pro is proprietary. Grok 4.1 Fast is proprietary.

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