The ALZ file extension refers to the ALZip Archive format developed by ESTsoft Corp. ALZip is a compression software that supports approximately 30 formats. ALZ files are ALZip Compressed Archives with no size limits, allowing large files like videos to be compressed.
On Windows 10, ALZ files are commonly used in China with the Google Chrome browser. To open an ALZ file, the ALZip software that created it is required. ALZip is available standalone or as part of the ALTools suite. Once installed, ALZ files will open with ALZip by default when double-clicked.
The Unarchiver program also uses the ALZip Archive format originally developed by Dag Agren of Circlesoft. So The Unarchiver can decompress ALZ files as well. More information on ALZip, The Unarchiver, and the ALZ format is available on the ESTsoft and Dag Agren websites.