Key Differences
- •Sonnet 4.5 has a larger context window (1M vs 400k tokens)
- •Sonnet 4.5 has more recent training data (Jan 2025 vs Sep 2024)
- •GPT-5.1 is more affordable for input ($1.25 vs $3.00/1M tokens)
- •GPT-5.1 is more affordable for output ($10.00 vs $15.00/1M tokens)
- •GPT-5.1 is newer (released Nov 2025)
400k tokens
Context
1M tokens
Sep 2024
Knowledge
Jan 2025
Nov 2025
Released
Sep 2025
$1.25/1M
Input
$3.00/1M
$10.00/1M
Output
$15.00/1M
Both GPT-5.1 and Sonnet 4.5 are available on Zo Computer. Try them both to see which one works best for your use case.