LZ File Format (.lz)
An LZ file is a single stream of data compressed with lzip, an LZMA-based command-line compressor that Antonio Diaz Diaz released in 2008 as a long-term-archival alternative to gzip, bzip2 and xz.
LZ at a glance#
| Full name | lzip compressed archive |
|---|---|
| File extension | .lz |
| Category | Archives |
| Developer | Antonio Diaz Diaz |
| First released | 2008 |
| MIME types | application/lzip |
| Compression | Lossless |
| Specification | draft-diaz-lzip: Lzip Compressed Format and the application/lzip Media Type |
| FileFlip support | FileFlip reads and writes this format |
What a .lz file can hold#
These are the things a LZ file either supports or does not, and they are what decides whether a conversion keeps everything or quietly drops something.
| Lossless compression | Yes |
|---|---|
| Streaming | Yes |
Strengths and limitations of LZ#
What LZ does well
- Splits output into independently-decodable members with their own CRC and size trailer, so lziprecover can salvage the undamaged parts of a corrupted file
- Matches xz for compression ratio, since both compress with the same LZMA algorithm
- Small, stable format specification with one implementation family, so files decoded today still decode decades from now
Where LZ falls short
- Compresses a single stream only, so packing more than one file means running tar first
- Almost no mainstream GUI archive tool supports it, unlike gzip, zip or even xz
- Compresses and decompresses slower than gzip at comparable settings
Pick lzip when an archive needs to survive years of storage or transmission and the ability to partially recover a damaged file matters more than having a GUI tool handle it.
Convert an LZ file to gzip or zip when it needs to open on a system whose tools stop at the common formats, which is most of them.
How to open a .lz file#
A .lz file opens in the programs below, grouped by the platform you are on. If you would rather not install anything, FileFlip converts LZ into a format your machine already opens, and it does it in the browser tab rather than on a server.
| Platform | Programs that open it |
|---|---|
| macOS | lzip (via Homebrew) |
| Linux | lzip, plzip, tar (with --lzip) |
| Web | FileFlip |
LZ questions people ask#
What's the difference between LZ and ZIP files?
An LZ file holds a single stream compressed with lzip, not a container of separate files like a ZIP. To pack more than one file as lzip, they need to be combined into a tar archive first and the result compressed as a .tar.lz.
Is lzip the same as LZMA?
Lzip is a specific file format and command-line tool built on the LZMA compression algorithm, the same algorithm 7z and xz also use. The three differ in the container wrapped around that compressed data, and an .lz file will not open with a tool that only understands .xz or .7z.
Why would I use lzip instead of xz?
Lzip trades some tool availability for a format built specifically so a corrupted archive can still be partially recovered, which is why long-term archival projects sometimes prefer it over xz. For everyday compression where recovery from bit rot is not a concern, xz has far broader tool support.
Converting LZ files#
Convert LZ to another format
Convert another format to LZ
Every conversion runs inside your browser. The file is read from your disk, the work happens on your own machine, and nothing is uploaded. How FileFlip works names the engine behind each family and how to verify that for yourself.