GLM / Z.ai (Zhipu AI) vs Codex (OpenAI)
Which one should you pick? Here's the full breakdown.
GLM / Z.ai (Zhipu AI)
Zhipu AI's open-weights family -- GLM-4.6 text flagship and GLM-4.6V multimodal, true MIT licensed
Codex (OpenAI)
OpenAI's cloud-based coding agent -- runs parallel tasks, proposes PRs, and lives inside ChatGPT
Powered by GPT-5.3-Codex / GPT-5.4
| Category | GLM / Z.ai (Zhipu AI) | Codex (OpenAI) |
|---|---|---|
| Ease of Use | 6.5 | 8.0 |
| Output Quality | 8.5 | 8.0 |
| Value | 9.0 | 8.0 |
| Features | 8.0 | 9.0 |
| Overall | 8.0 | 8.3 |
Pricing Comparison
| Feature | GLM / Z.ai (Zhipu AI) | Codex (OpenAI) |
|---|---|---|
| Free Tier | Yes | Yes |
| Starting Price | $0 | $0 |
Benchmark Head-to-Head
GLM-4.6 vs GPT-5.3-Codex
| Benchmark | GLM / Z.ai (Zhipu AI) | Codex (OpenAI) |
|---|---|---|
| HumanEval | 89.1% | 95% |
Which Should You Pick?
Pick GLM / Z.ai (Zhipu AI) if...
- ✓Better value for money (9/10)
Teams that need genuine MIT-licensed frontier open weights with no commercial strings. Especially strong for agentic workflows and vision (GLM-4.6V).
Visit GLM / Z.ai (Zhipu AI)Pick Codex (OpenAI) if...
- ✓Easier to use (8 vs 6.5)
- ✓More features (9 vs 8)
- ✓Stronger on python code generation (+5.9% on HumanEval)
Developers already paying for ChatGPT Plus who want a coding agent at no extra cost. Especially good for parallel task execution -- assign multiple bug fixes or feature branches and let Codex work them simultaneously.
Visit Codex (OpenAI)Our Verdict
Codex (OpenAI) edges out GLM / Z.ai (Zhipu AI) with a 8.3 vs 8.0 overall score. Both are solid picks, but Codex (OpenAI) has the advantage in features.