GPT-5.3 Codex vs Mercury 2: Specs & Benchmark Comparison
| Characteristic | GPT-5.3 Codex | Mercury 2 |
|---|---|---|
| Company | OpenAI | Inception |
| Release Date | February 5, 2026 | February 1, 2026 |
| Parameters | — | — |
| Multimodal | Yes | No |
| Context (input) | 400K | — |
| Context (output) | 128K | — |
| Input Price / 1M | $1.75 | — |
| Output Price / 1M | $14.00 | — |
| Average Score | 0.7 | 0.7 |
Verdict
Both models show equal results — the choice depends on your specific use case.
Overall Performance
Both models show comparable average scores: GPT-5.3 Codex — 0.7, Mercury 2 — 0.7.
Recency
Both models were released around the same time: 2/5/2026 and 2/1/2026.
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The GPT-5.3 Codex and Mercury 2 comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the GPT-5.3 Codex or Mercury 2 page. See also the complete list of AI model comparisons.