Side-by-side comparison of pricing, 12 benchmarks, and generation speed.
| Metric | GPT-5 Codex (high) | Mercury 2 |
|---|---|---|
| Input ($/M tokens) | $1.25 | $0.25 |
| Output ($/M tokens) | $10 | $0.75 |
Data from Artificial Analysis API — 12 benchmarks
Mercury 2 is cheaper overall. Its blended price (3:1 input/output ratio) is $0.38/M tokens vs $3.44/M for GPT-5 Codex (high).
GPT-5 Codex (high) wins 11 out of 12 benchmarks compared to 0 for Mercury 2. See the detailed benchmark chart above for per-category results.
Mercury 2 generates tokens faster at 907 tok/s vs 216 tok/s. However, Mercury 2 has lower time-to-first-token (3.76s vs 12.05s).
Choose based on your priorities: Mercury 2 for lower cost, GPT-5 Codex (high) for stronger benchmark performance, and Mercury 2 for faster generation. For latency-sensitive apps, check the TTFT comparison above.