GPT-5.5 Pro vs GLM 5.3 Prime
GLM 5.3 Prime is 16× cheaper than GPT-5.5 Pro on a blended basis. GPT-5.5 Pro has the larger context window at 1.1M tokens.
Side by side
Green marks the better value in each row where a comparison is meaningful.
| Attribute | GPT-5.5 Pro | GLM 5.3 Prime |
|---|---|---|
| Provider | OpenAI | Z.ai |
| Input / 1M tokens | $30.00 | $2.80 |
| Output / 1M tokens | $180 | $8.80 |
| Blended / 1M tokens | $67.50 | $4.30 |
| Cached input / 1M | - | $0.560 |
| Context window | 1.1M | 1M |
| Max output | 128K | 131K |
| Input modalities | file, image, text | text |
| Reasoning | Yes | Yes |
| Tool calling | Yes | Yes |
| Structured output | Yes | Yes |
| Prompt caching | No | Yes |
| Open weights | No | No |
| Knowledge cutoff | 2025-12-01 | - |
| Released | April 24, 2026 | September 23, 2026 |
Frequently asked
Is GPT-5.5 Pro or GLM 5.3 Prime cheaper?
GLM 5.3 Prime is 16× cheaper than GPT-5.5 Pro on a blended basis.
What is the price difference between GPT-5.5 Pro and GLM 5.3 Prime?
GPT-5.5 Pro costs $30.00 per million input tokens and $180 per million output tokens. GLM 5.3 Prime costs $2.80 and $8.80 respectively.
Which has the larger context window, GPT-5.5 Pro or GLM 5.3 Prime?
GPT-5.5 Pro, at 1.1M tokens versus 1M.