Ubuntu Package Search: Find, List and Hold Packages with APT

Updated: 11 October 2026 · Applies to: Ubuntu 26.04 (apt 3.2.0) and Ubuntu 24.04 (apt 2.8.3), tested; listing and holds also tested on Debian 13 (apt 3.0.3)

To search for a package on Ubuntu, refresh the package lists and run apt search with a keyword. It searches package names and descriptions in every repository your server uses. To see every available package, use apt list; to stop a package from being upgraded, put it on hold with apt-mark hold:

sudo apt update
apt search nginx                    # names and descriptions
apt search --names-only '^nginx'    # names only
apt show nginx                      # details of one package
apt list                            # every available package
sudo apt-mark hold nginx            # keep nginx at its current version
apt-mark showhold                   # list held packages
sudo apt-mark unhold nginx          # allow updates again

Search for a package (Ubuntu package search)

1. Refresh the lists first, so the search sees what the repositories offer now: sudo apt update. A search on old lists can miss new packages or show old versions.
2. Search names and descriptions. Each result shows the name, the repository suite, the version and the architecture, then the description. Lab output from Ubuntu 26.04, which found 58 packages for nginx:

   $ apt search nginx
   Sorting...
   Full Text Search...
   elpa-nginx-mode/resolute 1.1.10-1build1 all
     major mode for editing nginx config files
   
   golang-github-nginxinc-nginx-plus-go-client-dev/resolute 3.0.1-1 all
     client for NGINX Plus API for Go (library)
   
   libnginx-mod-http-auth-pam/resolute 1:1.5.5-4build3 amd64
     PAM authentication module for Nginx
   ...

3. Narrow it down. The search term is a regular expression, so ^ means "starts with" and $ "ends with". Several terms must all match:

   $ apt search --names-only '^nginx$'
   nginx/noble-updates,noble-security 1.24.0-2ubuntu7.18 amd64
     small, powerful, scalable web/proxy server
   $ apt search lightweight 'web server'
   caddy/resolute 2.6.2-14 amd64

   (The first result is from Ubuntu 24.04; output shortened.)
4. For one line per package, which is easier to read and to use in scripts, use apt-cache search. For example, to see which PHP-FPM version your release has (Ubuntu 26.04 below; Ubuntu 24.04 answered php8.3-fpm):

   $ apt-cache search --names-only '^php[0-9.]+-fpm$'
   php8.5-fpm - server-side, HTML-embedded scripting language (FPM-CGI binary)

5. Check a package before you install it. apt show nginx prints the version, section, size, dependencies, description and the repository (APT-Sources); apt-cache policy nginx shows the installed and candidate versions and where each comes from:

   $ apt-cache policy nginx
   nginx:
     Installed: (none)
     Candidate: 1.28.3-2ubuntu1.11
     Version table:
        1.28.3-2ubuntu1.11 500
           500 http://archive.ubuntu.com/ubuntu resolute-updates/main amd64 Packages
           500 http://security.ubuntu.com/ubuntu resolute-security/main amd64 Packages
        1.28.3-2ubuntu1 500
           500 http://archive.ubuntu.com/ubuntu resolute/main amd64 Packages

Find which package contains a command or file

Package names often differ from command names. With Ubuntu’s command-not-found package installed, typing a missing command tells you which package to install. In our test:

Command 'dig' not found, but can be installed with:
apt install bind9-dnsutils
Command 'ifconfig' not found, but can be installed with:
apt install net-tools

For any file, also ones that are not commands, use apt-file. It searches the contents of all available packages:

$ sudo apt install apt-file
$ sudo apt-file update
$ apt-file search --regexp '/usr/bin/dig$'
bind9-dnsutils: /usr/bin/dig
$ apt-file list bind9-dnsutils | head -4
bind9-dnsutils: /usr/bin/delv
bind9-dnsutils: /usr/bin/dig
bind9-dnsutils: /usr/bin/mdig
bind9-dnsutils: /usr/bin/nslookup

For a file that is already installed, dpkg -S /usr/bin/apt-file answers apt-file: /usr/bin/apt-file without any download.

Search Ubuntu packages online

packages.ubuntu.com searches package names, descriptions or source package names for one Ubuntu release (for example resolute for 26.04 or noble for 24.04), and its "Search the contents of packages" form finds the package that ships a file. This helps to check whether a package exists in your release before you change anything on the server. For Debian, use packages.debian.org.

Snap packages are a separate system: according to the Snapcraft documentation, snap find "media player" searches snap names and descriptions, and snap info NAME shows the channels and versions.

Unable to locate package

When apt cannot find a name, apt 3 on Ubuntu 26.04 prints Error: Unable to locate package NAME; apt 2.8 on 24.04 and apt-get print E: Unable to locate package NAME. Check, in this order:

1. The spelling, with apt search --names-only.
2. That you ran sudo apt update on this server at least once.
3. That the package exists in your release on packages.ubuntu.com. Packages are added and removed between releases.
4. That the right repository is enabled. apt only searches the repositories listed in /etc/apt/sources.list.d/. On Ubuntu 26.04 our test server had:

   $ grep -h -E '^(URIs|Suites|Components):' /etc/apt/sources.list.d/*.sources
   URIs: http://archive.ubuntu.com/ubuntu/
   Suites: resolute resolute-updates resolute-backports
   Components: main universe restricted multiverse
   URIs: http://security.ubuntu.com/ubuntu/
   Suites: resolute-security
   Components: main universe restricted multiverse

   If universe is missing, or the software needs a vendor repository or PPA, see how to list, add, enable and remove repositories on Ubuntu.

List available packages (the Ubuntu package list)

apt list prints every package the enabled repositories offer: on our test servers 78,922 on Ubuntu 26.04 and 87,454 on Ubuntu 24.04. Use a pattern in quotes and apt list -a for all versions of one package:

$ apt list "nginx*"
Listing...
nginx-common/resolute-updates,resolute-security 1.28.3-2ubuntu1.11 all
nginx-confgen/resolute 2.2-1build1 amd64
nginx-core/resolute-updates,resolute-security 1.28.3-2ubuntu1.11 all
...
$ apt list -a openssl
openssl/resolute-updates,resolute-security 3.5.5-1ubuntu3.7 amd64
openssl/resolute 3.5.5-1ubuntu3 amd64

apt-get has no list command (apt-get list fails with E: Invalid operation list). Its family tool apt-cache does the job: apt-cache pkgnames prints all names, apt-cache madison nginx all versions with their mirror. When you pipe apt into another command it warns apt does not have a stable CLI interface. Use with caution in scripts.; in scripts, prefer apt-cache and dpkg-query.

apt list --installed           # everything installed
apt list --manual-installed    # only what was installed on purpose
apt list --upgradable          # updates waiting after apt update

More ways to count and export installed packages: list installed packages on Ubuntu and Debian.

Hold a package (apt hold)

A hold stops APT from upgrading, removing or automatically installing a package, for example to keep a tested PHP, database or kernel version.

1. Hold one or more packages:

   $ sudo apt-mark hold libssl3t64
   libssl3t64 set on hold.

2. Check: apt-mark showhold lists the holds, and in dpkg -l a held package starts with hi.
3. Upgrade as usual. Ubuntu 24.04 lists the held package under The following packages have been kept back:; Ubuntu 26.04 and Debian 13 list it under Not upgrading:.
4. Remove the hold: sudo apt-mark unhold libssl3t64 (Canceled hold on libssl3t64.).

From our tests: a hold can also keep back packages that need the matching version (holding libaudit-common kept back libaudit1); unattended upgrades skip held packages (pkg openssl is on hold); and apt install -y on a held package stops with Held packages were changed and -y was used without --allow-change-held-packages. To keep the kernel series, hold linux-generic, linux-image-generic and linux-headers-generic, and unhold them later so security fixes arrive again.

Not every "kept back" package is held: according to Ubuntu, phased updates reach machines in stages and the message clears by itself. To pin or block versions in other ways, see lock package updates with APT; to install an exact version, see install a specific package version with apt; for a safe update routine, see update all packages on Linux safely.

Official documentation: apt, apt-mark, apt-file and Ubuntu: apt upgrade and phased updates.