Key Differences
- •GPT-5.5 has a larger context window (1.1M vs 400k tokens)
- •GPT-5.5 has more recent training data (Dec 2025 vs Aug 2025)
- •GPT-5.3 Codex is more affordable for input ($1.75 vs $5.00/1M tokens)
- •GPT-5.3 Codex is more affordable for output ($14.00 vs $30.00/1M tokens)
- •GPT-5.5 is newer (released Apr 2026)
400k tokens
Context
1.1M tokens
Aug 2025
Knowledge
Dec 2025
Feb 2026
Released
Apr 2026
$1.75/1M
Input
$5.00/1M
$14.00/1M
Output
$30.00/1M
Both GPT-5.3 Codex and GPT-5.5 are available on Zo Computer. Try them both to see which one works best for your use case.