GLM 5.1 vs GPT-5.5
| Z.ai GLM 5.1 | OpenAI GPT-5.5 | |
|---|---|---|
| Vendor | Z.ai | OpenAI |
| Context window | 200,000 | 1,050,000 |
| Max output | 128,000 | 128,000 |
| Reasoning | Yes | Yes |
| Tool calling | Yes | Yes |
| File input | No | Yes |
| Input | text | text, image |
| Output | text | text |
| Released | 2026-04-06 | 2026-04-23 |