GPT Image 2 vs Z.ai: GLM 5.3
| OpenAI GPT Image 2 | Z Ai Z.ai: GLM 5.3 | |
|---|---|---|
| Vendor | OpenAI | Z Ai |
| Context window | 128,000 | 1,048,576 |
| Max output | — | 131,072 |
| Reasoning | No | Yes |
| Tool calling | No | Yes |
| File input | Yes | No |
| Input | text, image | text |
| Output | image | text |
| Released | 2026-04-21 | — |