.deb File Extension

Learn what a .deb file is, how to inspect or install a Debian package safely, how Poly supports it, and which alternatives fit other systems.

File extension details for .deb

Storage Only
File typeDebian binary package
MIME type
EncodingBinary ar archive containing control and data tar archives
Operating systemsLinux, Windows, macOS
Opens withAPT, dpkg, dpkg-deb, File Roller
Poly supportYes. Poly stores, syncs, shares, versions, and downloads DEB packages.
Indexed by PolyPartial. Poly indexes the filename and ordinary file properties, not package metadata or archived contents.
Preview in PolyNo. Download the package to inspect it with Debian package tools.
Poly agentNo. The Poly agent cannot read the control metadata, scripts, or payload inside a DEB package.

What kind of file is a .deb?

A .deb file is usually a Debian binary package. It can contain a program's files, configuration, documentation, package metadata, and maintainer scripts. Its registered MIME type is application/vnd.debian.binary-package. Debian source packages use a different set of files led by .dsc, so “binary” describes the package type, not whether every payload file is executable.1

A modern DEB is an ar archive beginning with !<arch>\n, or 21 3C 61 72 63 68 3E 0A in hexadecimal. That signature identifies the outer container, not a valid package by itself. A normal package then has debian-binary, control.tar.*, and data.tar.* members in that order. A rarer multipart DEB uses debian-split as its first member instead.23

Renaming a TAR, RPM, or other installer to .deb does not convert it. Package-aware tools must validate the members, metadata, architecture, and dependencies.

How do I open a .deb on my computer?

On Debian, Ubuntu, and related Linux distributions, use APT or the distribution's software installer when you trust the package and intend to install it. To inspect without installing, dpkg-deb --info package.deb shows control information and dpkg-deb --contents package.deb lists payload paths.4

Windows users can run Debian tools inside WSL. On Windows or macOS, a Linux virtual machine or container offers the same package-aware inspection tools. A generic archiver may expose the outer members, but extraction does not resolve dependencies or perform a correct installation.5 Software packaged for Debian also may not run on another operating system or CPU architecture.

A DEB can contain maintainer scripts that run with administrator privileges. Prefer an authenticated repository. For a standalone download, verify the publisher and its checksum or signature before installation.5

Poly support for .deb

Poly recognizes DEB packages and stores, syncs, shares, versions, downloads, and finds them by filename and ordinary file properties.

Poly does not unpack the archive, index package fields or payload files, generate a thumbnail, or provide an in-app package browser. The Poly agent cannot read the control metadata, maintainer scripts, or archived contents. Download the package and inspect it with dpkg-deb when you need those details.

History of .deb

The current ar-based package format has been used since Debian 0.93 and is understood by dpkg 0.93.76 and later.2 Earlier DEB files used two lines of ASCII format information followed by two concatenated gzip-compressed tar archives.6

The modern format's debian-binary member currently declares version 2.0. IANA registered application/vnd.debian.binary-package in 2014 and lists application/x-debian-package and application/x-deb as deprecated names.5

Working with .deb and alternatives

Choose a package built for the target distribution, release, and architecture:

NeedBetter fit
Install on Debian or UbuntuDEB from a trusted APT repository
Supply the Debian installer.udeb, a reduced installer package
Build or distribute Debian source.dsc plus its source archives
Install on an RPM-family distributionRPM built for that system
Share files without installation behaviorTAR or ZIP

The package control record declares fields such as Architecture, Version, and Depends.7 Extracting files from a DEB therefore is not equivalent to installing it. Converting another installer can lose dependency rules, ownership, maintainer behavior, or distribution integration. Prefer a package produced and tested for the destination system.

Footnotes

  1. Debian Project. Debian FAQ: Basics of the Debian Package Management System.
  2. Debian dpkg maintainers. deb(5): Debian Binary Package Format. 2
  3. Debian dpkg maintainers. deb-split(5): Debian Multi-Part Binary Package Format.
  4. Debian dpkg maintainers. dpkg-deb(1): Debian Package Archive Manipulation Tool.
  5. Internet Assigned Numbers Authority. application/vnd.debian.binary-package Media Type Registration. 2 3
  6. Debian dpkg maintainers. deb-old(5): Old-Style Debian Binary Package Format.
  7. Debian Project. Debian Policy Manual: Binary Package Control Files.
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