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