OpenAI: GPT-5 Nano wins on more metrics (5 of 9), but the right pick depends on what you optimize for — see the breakdown below.
| Metric | OpenAI: GPT-5 Nano | Z.ai: GLM 4.5 |
|---|---|---|
| Intelligence Index | 25.9 | 26.4✓ |
| Coding Index | 22.9 | 26.3✓ |
| GPQA Diamond | 67% | 78%✓ |
| Design Arena Elo | 1146 | 1251✓ |
| Speed (tokens/sec) | 91✓ | 40 |
| Latency | 2.2s✓ | 2.4s |
| Input price /M | $0.050✓ | $0.600 |
| Output price /M | $0.400✓ | $2.20 |
| Context window | 400K✓ | 131K |
| Capabilities | ReasoningToolsJSONVision | ReasoningToolsJSON |