Key Differences
- •Sonnet 4.5 has a larger context window (1M vs 200k tokens)
- •Opus 4.5 has more recent training data (Mar 2025 vs Jan 2025)
- •Sonnet 4.5 is more affordable for input ($3.00 vs $5.00/1M tokens)
- •Sonnet 4.5 is more affordable for output ($15.00 vs $25.00/1M tokens)
- •Opus 4.5 is newer (released Nov 2025)
200k tokens
Context
1M tokens
Mar 2025
Knowledge
Jan 2025
Nov 2025
Released
Sep 2025
$5.00/1M
Input
$3.00/1M
$25.00/1M
Output
$15.00/1M
Both Opus 4.5 and Sonnet 4.5 are available on Zo Computer. Try them both to see which one works best for your use case.