Side-by-side comparison of pricing, 12 benchmarks, and generation speed.
| Metric | Claude Opus 4.5 (Reasoning) | GPT-5.5 (low) |
|---|---|---|
| Input ($/M tokens) | $6.25 | $5 |
| Output ($/M tokens) | $25 | $30 |
Data from Artificial Analysis API — 12 benchmarks
Claude Opus 4.5 (Reasoning) is cheaper overall. Its blended price (3:1 input/output ratio) is $10.94/M tokens vs $11.25/M for GPT-5.5 (low).
GPT-5.5 (low) wins 7 out of 12 benchmarks compared to 4 for Claude Opus 4.5 (Reasoning). See the detailed benchmark chart above for per-category results.
GPT-5.5 (low) generates tokens faster at 58 tok/s vs 54 tok/s. However, GPT-5.5 (low) has lower time-to-first-token (1.67s vs 11.25s).
Choose based on your priorities: Claude Opus 4.5 (Reasoning) for lower cost, GPT-5.5 (low) for stronger benchmark performance, and GPT-5.5 (low) for faster generation. For latency-sensitive apps, check the TTFT comparison above.