A plain-English reference to every common archive and file format you’re likely to run into, and what opens them.
Archive formats
These are “container” formats — they hold one or more files inside, usually compressed.
| Extension | Full name | Best tool | Notes |
|---|---|---|---|
.zip | ZIP archive | Built-in / 7-Zip / The Unarchiver | Universal. Our homepage has the full guide. |
.rar | WinRAR archive | 7-Zip / The Unarchiver | Opening guide. Better compression than ZIP. |
.7z | 7-Zip archive | 7-Zip / Keka | Opening guide. Highest common compression. |
.tar | Tape archive (uncompressed) | Built-in (all OSes) | Bundles files without compressing. Usually paired with gzip or bzip2. |
.tar.gz / .tgz | Gzipped tarball | Built-in / 7-Zip | Opening guide. Linux/Unix standard. |
.tar.bz2 | Bzip2 tarball | Built-in (Mac/Linux) / 7-Zip | Slower but smaller than gzip. |
.tar.xz | XZ tarball | Built-in / 7-Zip | Slowest to create, smallest output. |
.gz | Gzip file | Built-in / 7-Zip | Compresses a single file, not a folder. Often just decompresses to the same name minus .gz. |
.bz2 | Bzip2 file | Built-in / 7-Zip | Single-file compression. Slower than gzip. |
.xz | XZ file | Built-in (modern OSes) | Best compression for a single file. |
.cab | Windows Cabinet | Built-in Windows / 7-Zip | Old Microsoft installer format. |
.lzh / .lha | LHA archive | 7-Zip | Legacy, popular in Japan. |
.arj | ARJ archive | 7-Zip | 1990s DOS format. Still occasionally seen. |
.z | Unix compressed file | Built-in (Mac/Linux) | Pre-gzip. Very rare today. |
Disc images
| Extension | Full name | Best tool | Notes |
|---|---|---|---|
.iso | ISO disc image | Built-in (Win 10+ & Mac) | Full guide. Copy of an optical disc. |
.dmg | Apple Disk Image | Built-in (Mac) / 7-Zip (Win, limited) | Full guide. Mac app installer format. |
.img | Raw disk image | Built-in / 7-Zip / Etcher | Common for Raspberry Pi and embedded devices. |
.bin + .cue | BIN/CUE pair | 7-Zip / IsoBuster | Older CD copy format. Keep both files together. |
.mdf + .mds | Media Descriptor Format | Alcohol 120% / IsoBuster | Commercial disc imaging format. |
.vhd / .vhdx | Virtual hard disk | Built-in Windows / 7-Zip | Mounts as a virtual drive. |
Installer formats
| Extension | Platform | How to run |
|---|---|---|
.exe | Windows | Double-click. Executable — only run from trusted sources. |
.msi | Windows | Microsoft installer. Double-click. |
.msix / .appx | Windows 10/11 | Modern Windows installer. Double-click. |
.pkg | Mac | Double-click to run the installer. |
.deb | Debian/Ubuntu Linux | Double-click or sudo dpkg -i file.deb |
.rpm | Fedora/RedHat Linux | sudo dnf install file.rpm |
.apk | Android | Side-loaded app. Tap to install (requires enabling unknown sources). |
.ipa | iOS | Normally only installable via App Store or enterprise distribution. |
Other files you may find inside archives
Extracted an archive and found unfamiliar files? Here’s what some common ones are:
.pst/.ost— Microsoft Outlook email data. Import via Outlook..mbox— Email archive. Opens in Thunderbird, Apple Mail, and many other clients..csv/.tsv— Plain-text spreadsheet data. Opens in Excel, Google Sheets, any text editor..dat— Generic data file. Could be anything; context matters..xml/.json— Structured data. Opens in any text editor or browser..db/.sqlite— Database files. Use DB Browser for SQLite (free)..log— Plain-text log file. Opens in any text editor.