GPT-5 Codex vs Grok-3
OpenAI vs xAI — benchmarks, pricing, and capabilities side by side.
- •GPT-5 Codex has the higher intelligence index (87.1 vs 82.6)
- •GPT-5 Codex is cheaper ($1.25 vs $3.00 per 1M input)
- •GPT-5 Codex is faster
- •GPT-5 Codex has a larger context window (400K)
| GPT-5 Codex | Grok-3 | |
|---|---|---|
| Intelligence index | 87.1 | 82.6 |
| Developer | OpenAI | xAI |
| Type | Multimodal | Multimodal |
| Access | API only | API only |
| Context window | 400,000 tokens | 128,000 tokens |
| Input price | $1.25 / 1M | $3.00 / 1M |
| Output price | $10.00 / 1M | $15.00 / 1M |
| Speed | 180 tok/s | 100 tok/s |
| Released | September 23, 2025 | February 17, 2025 |
| Parameters | — | — |
| Input modalities | Text, Image | Text, Image |
| Output modalities | Text | Text |
Shared benchmarks
GPT-5 Codex
Grok-3
AIME 2025
98.7
93.3
GPQA Diamond
83.7
84.6
Humanity’s Last Exam
25.6
5.1
LiveCodeBench
84
79.4
MMLU-Pro
86.5
80