Free daily briefing on global business news.
The model topped OpenRouter usage charts anonymously before Z.ai claimed it and released its weights on Wednesday
Bloomberg / Getty Images
Z.ai confirmed Wednesday that it was behind Ox Alpha, the anonymous AI model that had been circulating on OpenRouter and topping usage charts, and released it under the name GLM-5.3-Flash. The company said every request to the model during its preview period was served on Chinese-made AI chips.
GLM-5.3-Flash carries 320 billion total parameters and 18 billion active parameters, the company said. According to Bloomberg, Z.ai set pricing at $0.15 per million tokens on the input side and $0.50 per million on the output side, putting it in the same low-cost bracket as DeepSeek. Z.ai also listed a per-task price of $0.045, which it said is roughly one-tenth the cost of comparable offerings.
