Z.ai: GLM 5.3 vs GPT-5.5
| Z Ai Z.ai: GLM 5.3 | OpenAI GPT-5.5 | |
|---|---|---|
| Vendor | Z Ai | OpenAI |
| Context window | 1,048,576 | 1,050,000 |
| Max output | 131,072 | 128,000 |
| Reasoning | Yes | Yes |
| Tool calling | Yes | Yes |
| File input | No | Yes |
| Input | text | text, image |
| Output | text | text |
| Released | — | 2026-04-23 |