Key Takeaways
GPT-5 Codex wins:
- Faster response time
- Higher intelligence benchmark
- Better at coding
- Better at math
GPT-5.1-Codex-Max wins:
- No clear advantages in compared metrics
Price Advantage
GPT-5 Codex
Benchmark Advantage
GPT-5 Codex
Context Window
GPT-5.1-Codex-Max
Speed
GPT-5 Codex
Pricing Comparison
Price Comparison
| Metric | GPT-5 Codex | GPT-5.1-Codex-Max | Winner |
|---|---|---|---|
| Input (per 1M tokens) | $1.25 | $1.25 | Tie |
| Output (per 1M tokens) | $10.00 | $10.00 | Tie |
| Cache Read (per 1M) | $125000.00 | $125000.00 | Tie |
Both models have similar overall pricing.
GPT-5 Codex Providers
OpenAI $1.25 (Cheapest)
GPT-5.1-Codex-Max Providers
OpenAI $1.25 (Cheapest)
Azure $1.25 (Cheapest)
Benchmark Comparison
6
Benchmarks Compared
0
GPT-5 Codex Wins
0
GPT-5.1-Codex-Max Wins
Benchmark Scores
| Benchmark | GPT-5 Codex | GPT-5.1-Codex-Max | Winner |
|---|---|---|---|
Intelligence Index Overall intelligence score | 44.5 | - | - |
Coding Index Code generation & understanding | 38.9 | - | - |
Math Index Mathematical reasoning | 98.7 | - | - |
MMLU Pro Academic knowledge | 86.5 | - | - |
GPQA Graduate-level science | 83.7 | - | - |
LiveCodeBench Competitive programming | 84.0 | - | - |
GPT-5 Codex significantly outperforms in coding benchmarks.
Cost vs Quality
X-axis:
Y-axis:
Loading chart...
GPT-5 Codex
Other models
Context & Performance
Context Window
GPT-5 Codex
400,000
tokens
Max output: 128,000 tokens
GPT-5.1-Codex-Max
400,000
tokens
Max output: 128,000 tokens
Speed Performance
| Metric | GPT-5 Codex | GPT-5.1-Codex-Max | Winner |
|---|---|---|---|
| Tokens/second | 314.7 tok/s | N/A | |
| Time to First Token | 10.95s | N/A |
Capabilities
Feature Comparison
| Feature | GPT-5 Codex | GPT-5.1-Codex-Max |
|---|---|---|
| Vision (Image Input) | ||
| Tool/Function Calls | ||
| Reasoning Mode | ||
| Audio Input | ||
| Audio Output | ||
| PDF Input | ||
| Prompt Caching | ||
| Web Search |
License & Release
| Property | GPT-5 Codex | GPT-5.1-Codex-Max |
|---|---|---|
| License | Proprietary | Proprietary |
| Author | OpenAI | OpenAI |
| Released | Sep 2025 | Dec 2025 |
GPT-5 Codex Modalities
Input
textimage
Output
text
GPT-5.1-Codex-Max Modalities
Input
textimage
Output
text