GPT-4o vs GPT-5.1-Codex
OpenAI vs OpenAI — benchmarks, pricing, and capabilities side by side.
- •GPT-5.1-Codex has the higher intelligence index (88.2 vs 56.4)
- •GPT-5.1-Codex is cheaper ($1.25 vs $2.50 per 1M input)
- •GPT-5.1-Codex is faster
- •GPT-5.1-Codex has a larger context window (400K)
| GPT-4o | GPT-5.1-Codex | |
|---|---|---|
| Intelligence index | 56.4 | 88.2 |
| Developer | OpenAI | OpenAI |
| Type | Multimodal | Multimodal |
| Access | API only | API only |
| Context window | 128,000 tokens | 400,000 tokens |
| Input price | $2.50 / 1M | $1.25 / 1M |
| Output price | $10.00 / 1M | $10.00 / 1M |
| Speed | 132 tok/s | 188 tok/s |
| Released | May 13, 2024 | November 13, 2025 |
| Parameters | — | — |
| Input modalities | Text, Image | Text, Image |
| Output modalities | Text | Text |
Shared benchmarks
GPT-4o
GPT-5.1-Codex
AIME 2025
25.7
95.7
GPQA Diamond
70.1
86
Humanity’s Last Exam
5.3
23.4
LiveCodeBench
42.5
84.9
MMLU-Pro
74.7
86