What is a LZH file? Learn about LZH files here

A LZH file is an compressed file, which means that it is a file that has been reduced in size. This is often done to speed up distribution over the Internet and to save storage space.

LZH file details

LZH is a file compressed with the Lempel-Zip-Huffman algorithms. They are mostly created by the Japanese LHA archiver created by Haruyasu Yoshizaki in 1988. It was originally named LHarc, later renamed to LH and finally to LHA.

The file format is not commonly used in Western countries, but is still quite popular in Japan. During the early versions of Doom and Quake, id software utilized LHA to compress their data files, and it was also the most popular compression format used on the Commodore Amiga.

To show how popular LZH files are in Japan, Microsoft launched a special add on for the Japanese version of Windows XP to support LZH files. This is known as the Microsoft Compressed (LZH) Folder Add-on.

There are sometimes confusion about the LHA and LZH file extensions. Aren't they the same? Yes, usually. A file with an .LZH extension is compressed with Lempel-Ziv-Huffman, but may be stored in a proprietary format. A file with the .LHA extension follows the format specified by Haruyasu Yoshizaki and used in the LHA archiver. Usually they are the same, though.

Opening LZH files and LHA files

If you are trying to open or create LZH files on a Windows PC, then you will need a tool like BitZipper. After installing BitZipper, you can open a LZH file simply by double-clicking it or by right-clicking on it in Windows Explorer, or by starting BitZipper and opening the LZH file the same way you open a document in your word processor.

Technical details

If you are looking for technical details and the complete history of the .LZH file format and the LHA archiver, please refer to this Wikipedia article.