27 August 2026

Chinese lab Z AI reveals mystery model as GLM-5.3-Flash

First reported

AI Business, TLDR AI and 1 other ran this on , all on the same day.

  • Z AI disclosed that Ox Alpha, an anonymous model that ranked highly on OpenRouter, is their new GLM-5.3-Flash.
  • GLM-5.3-Flash uses a mixture-of-experts architecture, a technique where only part of the model activates per query, enabling cheap inference.

Where they differ

Reported by AI Business