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o4-mini vs Grok 4.1 Fast

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

Quick Verdict

Grok 4.1 Fast is cheaper than o4-mini at $0.20/1M/1M vs $1.10/1M/1M input tokens — a 5.5x cost difference. o4-mini scores higher on quality benchmarks (ELO 1350). Choose Grok 4.1 Fast for cost-sensitive workloads; choose o4-mini for maximum quality.

Detailed Comparison

Metrico4-miniGrok 4.1 Fast
Input Price / 1M tokens$1.10/1M$0.20/1MCheaper
Output Price / 1M tokens$4.40/1M$0.50/1MCheaper
Context Window200K2MLarger
ELO Score (LMSYS)1350Smarter1305
Open Source
Free Tier
Release Date2025-042026-01

Which is cheaper: o4-mini or Grok 4.1 Fast?

Grok 4.1 Fast is the cheaper option at $0.20/1M per 1M input tokens, compared to $1.10/1M for o4-mini. That is a 5.5x cost difference on input tokens. Output pricing follows a similar pattern: o4-mini charges $4.40/1M/1M vs $0.50/1M/1M for Grok 4.1 Fast.

Which has better quality: o4-mini or Grok 4.1 Fast?

Based on LMSYS Chatbot Arena rankings, o4-mini achieves a higher ELO score (1350 vs 1305), suggesting stronger performance on open-ended tasks. o4-mini excels at cheapest reasoning model in the openai lineup. 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: o4-mini or Grok 4.1 Fast?

Choose o4-mini if:
  • Cheapest reasoning model in the OpenAI lineup
  • Strong performance on code and math for the price
  • 200K context window
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: o4-mini or Grok 4.1 Fast?

Grok 4.1 Fast is cheaper at $0.20/1M per 1M input tokens, making it 5.5x more affordable.

Which has better quality: o4-mini or Grok 4.1 Fast?

o4-mini scores higher on the LMSYS Chatbot Arena with an ELO of 1350, suggesting better overall quality for most tasks.

Which has a larger context window: o4-mini or Grok 4.1 Fast?

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

Should I choose o4-mini or Grok 4.1 Fast?

Choose Grok 4.1 Fast if cost is the priority. Choose o4-mini if benchmark quality is most important. Consider your specific use case: o4-mini is best for reasoning and coding, while Grok 4.1 Fast excels at long-context and low-cost.

Is o4-mini or Grok 4.1 Fast open source?

o4-mini is proprietary. Grok 4.1 Fast is proprietary.

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