OpenAI: GPT-5.2-Codex vs Z.ai: GLM 5.2
Z.ai: GLM 5.2 wins on more metrics (7 of 8), but the right pick depends on what you optimize for — see the breakdown below.
| Metric | OpenAI: GPT-5.2-Codex | Z.ai: GLM 5.2 |
|---|---|---|
| Intelligence Index | 40.1 | 51.1✓ |
| Coding Index | — | 68.8✓ |
| GPQA Diamond | 90%✓ | 90% |
| Design Arena Elo | — | — |
| Speed (tokens/sec) | 64 | 109✓ |
| Latency | 1.6s | 509ms✓ |
| Input price /M | $1.75 | $0.770✓ |
| Output price /M | $14.00 | $2.42✓ |
| Context window | 400K | 1.0M✓ |
| Capabilities | ReasoningToolsJSONVision | ReasoningToolsJSON |