Zip

Full support for the normal zip format, with additional support for AES encryption, Zip64 extensions for large files, Mac OS extensions of many different kinds, and several unusual compression methods. Can also extract .EXE self-extracting files using Zip.

Zipx

Full support for the new compression modes introduced by WinZip.

RAR

Including encryption and multiple volumes. Can also extract .EXE self-extracting files using RAR.

7z

All common compression methods are supported. Also supports Unix extensions.

LZMA, XZ

Both the old "LZMA-alone" format, usually named .lzma, and the new .xz format.

MSI

This format is also used by many other Microsoft formats, meanings that you can use The Unarchiver to extract internal data from DOC and PPT files, and others. There is probably no reason to do this, but you can.

NSIS

Supports many different versions, starting from version 1.10

EXE

Many kinds of .exe self-extracting formats are supported. However, if you find one that is not, please post an issue on the bug tracker.

ISO, BIN, MDF, NRG, CDI

Most common disc images can be unpacked, both normal and raw.

Split files

Can join files named .001, .002 that do not use any extra wrapper format.

StuffIt

Can unpack all files I've been able to locate.

StuffIt X

Can unpack many files, some more obscure features are still unsupported. JPEG compression is also unsupported.

DiskDoubler

Only lacks some old compression methods, because I have not been able to locate any files using these. If you have some that do not work, please post them here.

ARC, PAK

Full support for all algorithms, including proprietary ones from PAK. Encryption only works in command-line utilities.

Ace

No support for Ace 2.0 and up (WinAce).

ADF

Can extract files from Amiga disk images using the regular FFS file system.

DMS

Can extract files from compressed Amiga disk images using the regular FFS file system.

XAR

Suggested replacement for Tar on Unix. Used in some newer .pkg files on macOS.

RPM

Linux package format.

Deb

Linux package format.

Ar

Unix library format.

ALZip

Archive format which is mainly popular in South Korea. Support for all known compression methods, including Bzip2, Deflate and obfuscated Deflate.

WARC

Internet Archive Web Archive. Request and response headers also included in metadata.

NSA, SAR

Game data file. Can unpack all files I've found. If you have ones that do not unpack, please post an issue.

NDS

Nintendo DS ROM image, which can contain a file system.

SWF

Extracts images, sounds and music from Flash files.

PDF

Extracts bitmap images from PDF files. Especially useful for scanned PDFs.