Okular is a multiplatform universal document viewer developed by the K desktop environment (KDE) and based on Qt and KDE Frameworks libraries. Okular is released under the GPLv2+, and is thus fully Free Software.
It is distributed as part of the KDE Applications bundle. Its origins are from KPDF and it replaces KPDF, KGhostView, KFax, KFaxview and KDVI in KDE 4. Its functionality can be embedded in other applications. This application allows you to read PDF documents, comics and EPub books, visualize Markdown documents, browse images and much more.
Okular works well on low-end machines and also handles large PDF files effortlessly.
Okular comes with various features that lets you easily manage your documents. Some important features are listed here:
- Annotate your PDF Documents such as easily add popup notes and inline, underline text and highlight, you can also add your own text.
- With Selection mode you can copy and paste almost anything from your documents to elsewhere.
- Navigating your content is easier than ever. With Okular’s ‘Thumbnails panel’, you can browse graphically the part of the document you were looking for.
- You can view and verify digital signatures embedded in PDFs, check if they are still valid, and detect any modifications since the moment the document was signed.
- Reading text aloud using the Qt Speech module
- Can sign PDFs
- Cross platform application available for Linux, Windows, Mac OS X, *BSD
- Copy images to clipboard
This article explains two methods of installing Okular Document Viewer on Ubuntu 20.04.
Choose the installation method that is most appropriate for your environment.
Method 1: Installing Okular Document Viewer as a Snap Package
The easiest way to install Okular on Ubuntu 20.04 is by using the snap packaging system.
A snap package is a type of universal Linux package that you can enjoy irrespective of the distro. Its an self-contained software packages that include the binary all dependencies needed to run the application.
All you need is the snap service pre-configured, In the case of Ubuntu 20.04, it comes with snap pre-installed.
If snapd package is not already installed then you can install it by running following command.
$ sudo apt install snapd
Note: Snap packages can be installed from either the command-line or via the Ubuntu Software application.
This is actually the Snap version of the Okular Document Viewer. It can be used on any Linux distribution that has Snap support.
Open your terminal (
Ctrl+Alt+T) and type the following command to install the Okular package.
$ sudo snap install okular
At this step, you have successfully installed Okular application on Ubuntu 20.04 system.
If you are not comfortable with the command line, open Ubuntu Software, search for “Okular” and install the application.
Type the following command to update Okular package.
$ sudo snap refresh --list
Method 2: Installing Okular using APT
In this method we will install the Okular via
apt and the installation is very straightforward.
Okular Document Viewer is available in the universe repository of all Ubuntu releases.
Note: Though it is usually enabled by default, It won’t harm to enable universe repository first.
$ sudo add-apt-repository universe
Then type the following command to update the package index.
$ sudo apt update && sudo apt upgrade
Finally execute the following command to install Okular Document Viewer on Ubuntu.
$ sudo apt install okular
At this step, you have successfully installed Okular Document Viewer application on Ubuntu 20.04 system.
Starting Okular Document Viewer
Okular can be launched from the command line by typing
okular or by clicking on the Colorpicker icon (
Okular User Interface:
How to Uninstall Okular from Ubuntu 20.04
For some reason, If you want to uninstall Okular application, refer following steps.
If you have installed Okular Document Viewer via Snap type the following command:
$ sudo snap remove okular
If you have installed the appication using
apt then uninstall by running the below command:
$ sudo apt-get remove okular
I hope that now you have a good understanding of How to install Okular Document Viewer on Ubuntu 20.04 LTS Focal Fossa.
If anyone does have any questions about what we covered in this guide then feel free to ask in the comment section below and I will do my best to answer those.