Compress to Any Archive Format
Create archives in 32+ formats including ZIP, RAR, 7Z, TAR, ISO, CAB with advanced compression options
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What the compression level actually changes
The level slider is the main choice this tool gives you, so we measured what each setting is worth. We packed the same folder at every level and recorded both the size and the time it took.
Tested on 2.3 MB of source code, logs and CSV data, packed with 7-Zip 26.02 at each level.
| Format | Level | Result | Saved | Time to pack |
|---|---|---|---|---|
| ZIP | 0 | 2.3 MB | -0.2% | 188 ms |
| ZIP | 1 | 0.5 MB | 77.6% | 94 ms |
| ZIP | 5 | 0.4 MB | 80.8% | 170 ms |
| ZIP | 6 (default) | 0.4 MB | 80.8% | 164 ms |
| ZIP | 9 | 0.4 MB | 81.4% | 724 ms |
| 7Z | 1 | 0.4 MB | 84.7% | 89 ms |
| 7Z | 5 (default) | 0.3 MB | 85.8% | 276 ms |
| 7Z | 9 | 0.3 MB | 86.3% | 338 ms |
- Level 1 does most of the work. On ZIP it already saved 77.6%, against 81.4% at level 9. The last eight levels are worth under 3.8 percentage points combined.
- Maximum compression costs a lot of time for very little gain. ZIP level 9 took 724 ms against 164 ms at the default level 6, roughly 4 times longer, to save another 0.6 points.
- Level 0 means no compression at all. It stored the folder at 2.3 MB, the same size as the original, which is useful only when you want a single file rather than a smaller one.
- 7Z beat ZIP at every level, saving 85.8% at its default against ZIP's 80.8%. If size is what matters and the recipient can open 7Z, it is the better choice.
Which level should you pick
For almost everything, the default is the right answer. Raise the level only when you are packing something large that you will send many times, and the extra minutes of packing are worth a fraction of a percent. Lower it when speed matters more than size.
Measured on one representative folder. Files that are already compressed, such as photographs, video and music, barely shrink at any level: the same ZIP settings saved only 13.6% on a folder of JPEGs and MP3s.
Supported Archive Formats
Create archives in all major compression formats
Common Archives
The universal archive format, supported everywhere.
Levels 0 to 9, with 6 as the default.
Level 1 already captures most of the saving.
A proprietary format from RARLAB.
Recompressed on our servers at your chosen level.
Creating RAR needs licensed software; 7Z is the open alternative.
The open 7-Zip format, using LZMA2 by default.
Levels 0 to 9, with 5 as the default.
Gave the smallest archives of anything we measured.
Unix/Linux Archives
A Unix container that bundles files without compressing them.
There is no level to set; TAR does not compress.
Pair it with gzip, bzip2 or xz to actually save space.
A TAR archive compressed with gzip.
Levels 1 to 9 apply to the gzip stage.
The most common compressed tarball on Unix systems.
A TAR archive compressed with bzip2.
Levels 1 to 9 apply to the bzip2 stage.
Smaller than gzip, but noticeably slower to pack.
Specialized Formats
A complete disc image, sector for sector.
Stored as-is; ISO has no compression stage.
Convert to 7Z or ZIP if you need it smaller.
Microsoft's cabinet format, used by Windows installers.
Recompressed server-side at your chosen level.
Convert to ZIP for everyday sharing.
The classic Unix archive format.
A container only, so there is no level to set.
Used for static libraries and Debian package internals.
A Debian and Ubuntu software package.
Repacked with its internal tarballs recompressed.
Keep the original if you plan to install from it.
A Red Hat, Fedora and SUSE software package.
Repacked server-side at your chosen level.
Keep the original for installation.
A Java archive, structurally a ZIP file.
Uses the same DEFLATE levels as ZIP.
Compresses well because class files are text-like.
A DOS-era archive format from the early 1990s.
Recompressed on our servers.
Convert to 7Z or ZIP for anything you still need.
A Japanese archive format popular in the 1990s.
Recompressed on our servers.
Largely historical; move the contents forward.
A Unix archive used by initramfs images and RPMs.
A container, usually paired with gzip or xz.
On its own it does not compress.
References
- APPNOTE.TXT: .ZIP File Format Specification - PKWARE
- RFC 1951: DEFLATE Compressed Data Format Specification version 1.3 - RFC Editor
- RFC 1952: GZIP file format specification version 4.3 - RFC Editor
- 7z Format - 7-Zip
- The .xz File Format - Tukaani Project
- bzip2 Manual - Sourceware
- pax, including the tar archive format - POSIX.1-2017, The Open Group
- Compression Streams API - MDN Web Docs, Mozilla