GPT-5.5 Pro vs Z.ai: GLM 5.3 FlashX
openai/gpt-5.5-pro · z-ai/glm-5.3-flashx
As of October 31, 2026, Z.ai: GLM 5.3 FlashX is the cheaper API on UberLLM: $0.1484 per million input tokens and $0.5012 per million output, versus $24.30 / $145.80 for GPT-5.5 Pro, about 100% less when output is 3 tokens for every input token. These are the median prices buyers paid over the last 24 hours. Both work with one OpenAI-compatible key and UberLLM adds no fee. Choose Z.ai: GLM 5.3 FlashX to cut cost; choose GPT-5.5 Pro when its capabilities fit your task better.
GPT-5.5 Pro vs Z.ai: GLM 5.3 FlashX, side by side
| Spec | GPT-5.5 Pro | Z.ai: GLM 5.3 FlashX |
|---|---|---|
| Price · input / 1M | $24.30 | $0.1484 |
| Price · output / 1M | $145.80 | $0.5012 |
| Context length | 1,000,000 | 1,048,576 |
| Max output tokens | 128,000 | 131,072 |
| Input modalities | text, image | text, image, video |
| Output modalities | text | text |
| Tools / functions | Yes | Yes |
| Vision (image input) | Yes | Yes |
| Reasoning | Yes | Yes |
| % off list | 19% off | 60% off |
Median prices buyers paid on UberLLM over the last 24 hours. No UberLLM fee on requests; adding credit by card costs 5.5% + $0.50. Updated October 31, 2026.
GPT-5.5 Pro vs Z.ai: GLM 5.3 FlashX — FAQ
Is GPT-5.5 Pro or Z.ai: GLM 5.3 FlashX cheaper?
Z.ai: GLM 5.3 FlashX is cheaper on a blended token mix, by about 100%. A request costs what its provider charged, UberLLM adds no fee, and every request is listed with its cost in Activity.
What's the price difference between GPT-5.5 Pro and Z.ai: GLM 5.3 FlashX?
GPT-5.5 Pro: $24.30 in / $145.80 out per 1M tokens. Z.ai: GLM 5.3 FlashX: $0.1484 in / $0.5012 out per 1M tokens. That's roughly a 100% blended difference. Prices are live; UberLLM adds no fee.
Can I use both GPT-5.5 Pro and Z.ai: GLM 5.3 FlashX with one API?
Yes. Both are served through a single OpenAI-compatible endpoint — set the base URL to https://api.uberllm.dev/v1 and your UberLLM key, then switch between them by changing the model id. Anthropic SDKs work via https://api.uberllm.dev/v1/messages.