What is a .deb file?
Debian Package · Disk image · Debian · 1990s
A DEB is a software package for Debian-based Linux systems like Ubuntu. It bundles a program's files with its metadata, dependency list and install scripts, and you install it with the system's package tools rather than opening it directly.
What is a .deb file used for?
Under the hood a .deb is an ar archive containing the app's files plus control information that tells the system what it needs and what to run during install.
You install one by double-clicking it into a graphical Software Center, or from the terminal with sudo apt install ./file.deb (which also pulls in dependencies) or sudo dpkg -i file.deb.
DEB packages only apply to Debian and its relatives (Ubuntu, Mint and so on). The Red Hat world uses RPM instead.
What opens a .deb file?
The .deb format opens in the following apps, grouped by operating system. If one app does not work, try another from the same list.
Windows
- Not applicable (inspect with 7-Zip)
macOS
- Not applicable (inspect with an archive tool)
Linux
- Software Center
- apt
- dpkg
- Archive Manager (to inspect)
Web
- Not applicable
Open a .deb file step by step
- Confirm the file really is a .deb. Drop it into the WhatFileType identifier, which reads its signature in your browser without uploading anything.
- On Windows, open it with Not applicable (inspect with 7-Zip).
- On Mac, use Not applicable (inspect with an archive tool).
- On Linux, try Software Center or apt.
- Still stuck? Convert the .deb to Not convertible, which opens more widely.
Why can't I open my .deb file?
Almost always because no installed app understands DEB. Install one of the apps above, or convert the file to a format your existing software already reads. If double-clicking opens the wrong program instead of nothing at all, the file association is set to the wrong app rather than the file being broken.
The other possibility is that the file is not really a .deb at all. Drop it into the file identifier to check it by its bytes instead of its name. Nothing is uploaded.
How to convert a .deb file
You can convert a .deb file to Not convertible using a conversion tool or the export menu of an app that opens it.
What is the .deb file signature (magic bytes)?
A .deb file starts with the hex bytes 21 3C 61 72 63 68 3E, which read as !<arch> in ASCII. Programs identify DEB by those bytes, not by the filename, so a renamed file still gives itself away.
These are the documented signatures for DEB. For a full breakdown, see the Debian package file signature page.
| Hex signature | Offset | ASCII | Note |
|---|---|---|---|
| 21 3C 61 72 63 68 3E | 0 | !<arch> | '!<arch>' (a .deb is an ar archive) |
See the full magic-numbers reference for every format.
Frequently asked questions
What is a .deb file?
A DEB is a software package for Debian-based Linux systems like Ubuntu. It bundles a program's files with its metadata, dependency list and install scripts, and you install it with the system's package tools rather than opening it directly.
How do I install a .deb file?
Double-click it to open your distribution's Software Center, or run sudo apt install ./file.deb in a terminal, which installs it and its dependencies. sudo dpkg -i file.deb also works but does not resolve dependencies.
Is a .deb file safe?
Installing one runs with root privileges, so it is only as safe as its source. Stick to official repositories and vendor downloads, and be cautious with a .deb from an unknown site.
Related formats
Sources
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