Key Differences
- •Grok 4.1 Fast Reasoning has a larger context window (2M vs 400k tokens)
- •Grok 4.1 Fast Reasoning has more recent training data (Nov 2024 vs Sep 2024)
- •Grok 4.1 Fast Reasoning is more affordable for input ($0.20 vs $1.25/1M tokens)
- •Grok 4.1 Fast Reasoning is more affordable for output ($0.50 vs $10.00/1M tokens)
- •Grok 4.1 Fast Reasoning is newer (released Nov 2025)
400k tokens
Context
2M tokens
Sep 2024
Knowledge
Nov 2024
Nov 2025
Released
Nov 2025
$1.25/1M
Input
$0.20/1M
$10.00/1M
Output
$0.50/1M
Both GPT-5.1 and Grok 4.1 Fast Reasoning are available on Zo Computer. Try them both to see which one works best for your use case.