GPT-5.1 vs Mercury 2
OpenAI vs Inception — benchmarks, pricing, and capabilities side by side.
- •GPT-5.1 has the higher intelligence index (89 vs 77)
- •Mercury 2 is cheaper ($0.25 vs $1.25 per 1M input)
- •Mercury 2 is faster
- •GPT-5.1 has a larger context window (400K)
| GPT-5.1 | Mercury 2 | |
|---|---|---|
| Intelligence index | 89 | 77 |
| Developer | OpenAI | Inception |
| Type | LLM | LLM |
| Access | API only | API only |
| Context window | 400,000 tokens | 128,000 tokens |
| Input price | $1.25 / 1M | $0.25 / 1M |
| Output price | $10.00 / 1M | $0.75 / 1M |
| Speed | 115 tok/s | 790 tok/s |
| Released | November 12, 2025 | March 4, 2026 |
| Parameters | — | — |
| Input modalities | Text, Image | Text |
| Output modalities | Text | Text |
Shared benchmarks
GPT-5.1
Mercury 2
GPQA Diamond
88.1
77
Humanity’s Last Exam
26.5
15.5