Chinese tech company Z.ai says it was behind the mysterious free AI model, Ox Alpha, that generated buzz for its performance.
In a blog post published on Wednesday, Z.ai said Ox Alpha was an anonymous preview of its new GLM-5.3-Flash model, tested on OpenRouter and OpenCode to gather user feedback before its release.
The company said it has made the model’s weights publicly available on the platform Hugging Face, allowing developers to download, modify, and build on it.
Z.ai said the model is multimodal, meaning it can work with text, images, and video, and has a context window of up to 1 million tokens.
Last week, Ox Alpha became a subject of…
