GPT-5 vs. GPT-5-Codex: A Head-to-Head Analysis (2026)
A detailed comparison of GPT-5 and GPT-5-Codex, analyzing quality, coding, math, speed, and cost to determine the best model for different use cases.
Here's a detailed comparison of GPT-5 and GPT-5-Codex, assessing their strengths across various metrics.
| Metric | GPT-5 | GPT-5-Codex |
|---|---|---|
| Quality Index | 44.6 | 44.6 |
| Coding Index | 36.0 | 38.9 |
| Math Index | 94.3 | 98.7 |
| Blended Price | $3.44/1M tokens | $3.44/1M tokens |
| Output Speed | 72 tok/s | 169 tok/s |
| Open Source | No | No |
| Parameters | N/A | N/A |
Quality Analysis
Both models exhibit a Quality Index of 44.6, indicating similar general capabilities. This suggests that for tasks requiring broad knowledge and reasoning, neither model holds a distinct advantage. Tie: GPT-5 and GPT-5-Codex.
Coding and Math Analysis
GPT-5-Codex outperforms GPT-5 in both coding and math. Specifically, GPT-5-Codex achieves a Coding Index of 38.9 compared to GPT-5's 36.0. In mathematics, GPT-5-Codex scores 98.7 versus GPT-5's 94.3. This positions GPT-5-Codex as the superior choice for applications heavily reliant on coding and mathematical reasoning. Winner: GPT-5-Codex.
Inference Economics
Since both models share the same blended price of $3.44 per 1M tokens and have similar Quality Index scores, the cost per quality point is effectively the same. However, given GPT-5-Codex's enhanced coding and math abilities, it offers slightly better value for specialized tasks within those domains. Winner: GPT-5-Codex due to specialized performance.
Latency Analysis
The most significant difference lies in output speed. GPT-5-Codex generates text at 169 tokens per second (tok/s), while GPT-5 outputs at 72 tok/s. This translates to GPT-5-Codex being more than twice as fast. For latency-sensitive applications, this difference is critical. Winner: GPT-5-Codex.
Deployment Scenarios
- Coding-Focused: GPT-5-Codex is the clear winner due to its higher coding index and faster output speed.
- General Use: The similar Quality Index scores suggest either model could be used, but GPT-5-Codex's faster speed provides a better user experience.
- Budget-Constrained: Given the identical pricing, the faster GPT-5-Codex delivers more value per dollar.
- Enterprise Applications: The enhanced speed and specialized capabilities of GPT-5-Codex make it preferable for enterprise-level deployments where efficiency and accuracy are paramount.
Final Verdict
GPT-5-Codex emerges as the superior model. While both share similar general quality, GPT-5-Codex's enhanced coding and math capabilities, coupled with a significantly faster output speed, make it the more versatile and efficient choice across various deployment scenarios.
For users seeking a balance of quality, speed, and specialized expertise, GPT-5-Codex is the recommended option. Explore more models at Explore or use the LLM Selector to find the best LLM for your needs.