GLM 5.1 vs GLM 5.3 Flash
z-ai/glm-5.1 · z-ai/glm-5.3-flash
As of October 31, 2026, GLM 5.3 Flash is the cheaper API on UberLLM: $0.0008 per million input tokens and $0.0070 per million output, versus $0.0693 / $0.2178 for GLM 5.1, about 97% 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 GLM 5.3 Flash to cut cost; choose GLM 5.1 when its capabilities fit your task better.
GLM 5.1 vs GLM 5.3 Flash, side by side
| Spec | GLM 5.1 | GLM 5.3 Flash |
|---|---|---|
| Price · input / 1M | $0.0693 | $0.0008 |
| Price · output / 1M | $0.2178 | $0.0070 |
| Context length | 200,000 | 1,048,576 |
| Max output tokens | 24,000 | 131,072 |
| Input modalities | text | text, image, video |
| Output modalities | text | text |
| Tools / functions | Yes | Yes |
| Vision (image input) | — | Yes |
| Reasoning | Yes | Yes |
| % off list | 95% off | 95% 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. A price more than 70% below list is what buyers were billed, not an error. Why so cheap?
GLM 5.1 vs GLM 5.3 Flash — FAQ
Is GLM 5.1 or GLM 5.3 Flash cheaper?
GLM 5.3 Flash is cheaper on a blended token mix, by about 97%. 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 GLM 5.1 and GLM 5.3 Flash?
GLM 5.1: $0.0693 in / $0.2178 out per 1M tokens. GLM 5.3 Flash: $0.0008 in / $0.0070 out per 1M tokens. That's roughly a 97% blended difference. Prices are live; UberLLM adds no fee.
Can I use both GLM 5.1 and GLM 5.3 Flash 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.