Claude Opus 5.5 vs GPT-5.3-Codex
| Claude Opus 5.5 | GPT-5.3-Codex | |
|---|---|---|
| Coding index | 88.8 | 60.0 |
| Benchmarks behind it | Verified, 5 benchmarks | Verified, 3 benchmarks |
| Output $/Mtok | $20.00 | $14.00 |
| Cost per solved task | Not computable | $0.59 |
| Context window | 1M | 400K |
| Claude Opus 5.5 | GPT-5.3-Codex | |
|---|---|---|
| Coding index | 88.8 | 60.0 |
| Benchmarks behind it | Verified, 5 benchmarks | Verified, 3 benchmarks |
| Output $/Mtok | $20.00 | $14.00 |
| Cost per solved task | Not computable | $0.59 |
| Context window | 1M | 400K |