How to Open an LZH File on Windows 11 and Mac
An .lzh (or .lha) file is an archive made with LHA, the compression tool that was standard in Japan through the 1990s and 2000s. Current Windows and macOS cannot open it, but it is easy to extract, and it is safe as long as you do not run what comes out of it.
Why it will not open
- Windows dropped it. Japanese editions of Windows 7 through Windows 10 version 1607 could extract LZH out of the box; version 1703 (the 2017 Creators Update) removed the feature, so Windows 10 and 11 today only ask which app to use. XP and Vista needed a free Microsoft add-on.
- macOS never had it. Archive Utility opens ZIP, gzip and a few others, not LZH.
- The format was retired. In 2010 the maintainer of UNLHA32.DLL, the library behind most Windows LZH tools, announced the end of development and asked people to stop using LZH. Files still exist; new tools rarely bother.
How to open it
In the browser, nothing to install
- 1 Drop the .lzh file into the LZH extractor on this site. The file list appears at once; Japanese file names are decoded correctly.
- 2 Save the files you need one by one, or "Save all as ZIP" to get a ZIP that opens on any system.
- 3 Nothing is uploaded: the archive is read in your browser.
Windows: 7-Zip, Lhaplus or Explzh
- 1 7-Zip (free, 7-zip.org) opens LZH: right-click the file → 7-Zip → Extract Here.
- 2 Lhaplus and Explzh are the Japanese archivers most offices already have; both open LZH and handle Shift_JIS names.
- 3 If you cannot install software on the PC, use the browser method above.
macOS: The Unarchiver
- 1 Install The Unarchiver from the App Store (free). It opens LZH and decodes the Japanese names.
- 2 Double-click the .lzh file; if it still opens with Archive Utility, right-click → Open With → The Unarchiver.
Why the names may come out garbled
LHA wrote file names in Shift_JIS, the Japanese encoding of the DOS and Windows era. A tool that assumes UTF-8 shows them as nonsense or drops them. 7-Zip, Lhaplus, Explzh, The Unarchiver and the extractor on this site all read Shift_JIS names correctly.
Do not send new files as LZH
ZIP is built into every system and supports the same content. The 2010 retirement was prompted by a real problem: crafted LZH headers could slip past antivirus scanners. Extracting an LZH you received is fine; creating new ones is not worth the trouble it causes the recipient.