GPT-5.3-Codex vs Mistral Medium 3.5
OpenAI vs Mistral AI — benchmarks, pricing, and capabilities side by side.
- •GPT-5.3-Codex has the higher intelligence index (91.5 vs 74.8)
- •Mistral Medium 3.5 is cheaper ($1.50 vs $1.75 per 1M input)
- •Mistral Medium 3.5 is faster
- •GPT-5.3-Codex has a larger context window (400K)
| GPT-5.3-Codex | Mistral Medium 3.5 | |
|---|---|---|
| Intelligence index | 91.5 | 74.8 |
| Developer | OpenAI | Mistral AI |
| Type | Multimodal | Multimodal |
| Access | API only | API only |
| Context window | 400,000 tokens | 262,144 tokens |
| Input price | $1.75 / 1M | $1.50 / 1M |
| Output price | $14.00 / 1M | $7.50 / 1M |
| Speed | 73 tok/s | 140 tok/s |
| Released | February 24, 2026 | April 30, 2026 |
| Parameters | — | — |
| Input modalities | Text, Image | Text, Image |
| Output modalities | Text | Text |
Shared benchmarks
GPT-5.3-Codex
Mistral Medium 3.5
GPQA Diamond
91.5
74.8
Humanity’s Last Exam
39.9
12.8