o3 vs Grok 4.1 Fast
Pricing, context window, and benchmark comparison · Last updated April 2026
Grok 4.1 Fast is cheaper than o3 at $0.20/1M/1M vs $2.00/1M/1M input tokens — a 10.0x cost difference. o3 scores higher on quality benchmarks (ELO 1395). Choose Grok 4.1 Fast for cost-sensitive workloads; choose o3 for maximum quality.
Which is cheaper: o3 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 o3. That is a 10.0x cost difference on input tokens. Output pricing follows a similar pattern: o3 charges $8.00/1M/1M vs $0.50/1M/1M for Grok 4.1 Fast.
Which has better quality: o3 or Grok 4.1 Fast?
Based on LMSYS Chatbot Arena rankings, o3 achieves a higher ELO score (1395 vs 1305), suggesting stronger performance on open-ended tasks. o3 excels at top-tier reasoning on math, science, and agentic tasks. 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: o3 or Grok 4.1 Fast?
- → Top-tier reasoning on math, science, and agentic tasks
- → 87% cheaper than original o1 at the same capability tier
- → 200K context window
- → 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: o3 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: o3 or Grok 4.1 Fast?
o3 scores higher on the LMSYS Chatbot Arena with an ELO of 1395, suggesting better overall quality for most tasks.
Which has a larger context window: o3 or Grok 4.1 Fast?
Grok 4.1 Fast has a larger context window at 2000K tokens.
Should I choose o3 or Grok 4.1 Fast?
Choose Grok 4.1 Fast if cost is the priority. Choose o3 if benchmark quality is most important. Consider your specific use case: o3 is best for reasoning and math, while Grok 4.1 Fast excels at long-context and low-cost.
Is o3 or Grok 4.1 Fast open source?
o3 is proprietary. Grok 4.1 Fast is proprietary.