How to Open, Edit,and Convert LZH Files

Screenshot of several LZH files in Windows 10 that open with PeaZip
LZH Files.


A file with the LZH file extension is an LZH Compressed file that's been compressed with the Lempel-Ziv and Haruyasu algorithm, which are the names of the algorithm's inventors.

This compression format is popular in Japan but not really anywhere else. Though it has been used to compress video game installation files, like those in id Software's Doom and Quake, as well as used as the archive format in the Amiga computer.

LZH files are like other compression formats (e.g. ZIP, 7Z, RAR) in that their purpose is twofold - two both reduce the size of files and to hold multiple files together in one single archive.

The LZH format has basically replaced the original LHARC Compressed Archive (.LHA) format (which was previously named LHarc and then LH) that it was originally based on.

How to Open an LZH File

Japanese versions of the Windows operating system include an add-on to natively support LZH files without having to use any extra software. But if you're running a non-Japanese version, you can still open the LZH file using third-party software.

We know of several programs that can do this. Our favorites are 7-Zip and PeaZip, (which both support the LHA format too), but there are some others out there, too.

If you'd prefer, you should also be able to open LZH files on non-Japanese Windows installs without these programs so long as you install the add-on called Microsoft Compressed (LZH) Folder Add-on. You can get this through Windows Update with the Japanese language pack (Microsoft explains how), but you must be using an Enterprise or Ultimate version of Windows 7 to do this.

If you find that an application on your PC does try to open the LZH file but it's the wrong application, or if you would rather have another installed program open LZH files, you can change the default program for a specific file extension.

How to Convert an LZH File

It's rarely a necessary task to convert an archive file format like LZH to another type of archive because it's unlikely that you want to save the actual LZH file to another format. It's more likely that it's a file inside the archive that you want to be converted.

For example, if you have some PDF files inside an LZH file, converting the whole LZH file to another archive format wouldn't accomplish much. What you'd want to do instead is extract the PDFs out of the LZH file and then convert the PDFs to a new format.

Once you've extracted the file from the LZH archive, use a conversion program if you want to convert it to a new file format.

However, we do know of a couple LZH converters that can save the LZH file to an archive format like ZIP, 7Z, CAB, TAR, YZ1, GZIP, BZIP2, TBZ, etc. Just remember that doing this does not convert the files inside (which is likely what you want to do), but instead just converts the whole archive file itself.

FileZigZag and Zamzar are two online file converters that can do this. With these tools, you have to first upload your LZH file to one of those websites before you can convert it, after which you have to then download the file back to your computer before you can use it.

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