How to Install Nomacs on Ubuntu 20.04 LTS

Nomacs is an open-source, free image viewer that supports multiple platforms. You can use it for viewing all standard formats, including RAW and PSD files, by tapping on the widget with additional information such as thumbnails or histograms revealed beneath its semi-transparent surface – no need to open up another app!

The imaging software also contains many features, such as it can be used to adjust the brightness, contrast, and hue of an image while maintaining saturation. It also has a pseudo color function that allows you to create false colors studies in one go with ease! Another unique feature about nomac’s software is its ability for multiple instances where it will sync up any changes made from different zoom levels or panning motions, so they match perfectly on screen at all times – making review sessions much more informative than before as well because viewers can see exactly how things changed when zooming around inside each photo frame.

In the following tutorial, you will learn how to install Nomacs Image Viewer on Ubuntu 20.04 LTS Focal Fossa using the Ubuntu default repository or alternative flatpak installation manager for those that may want to use a much-updated version.

Update Ubuntu

Before going into the tutorial, the first step is to run an apt update, which ensures your system is up-to-date to avoid any conflicts.

sudo apt update && sudo apt upgrade -y

Install Nomacs – APT Method

The first option is to install the image viewer using the apt command from Ubuntu 20.04 repository. For most users, this is the most recommended way to install.

In your terminal, use the following command to install the text editor.

sudo apt install nomacs -y

Install Nomacs- Flatpak Method

The second option is to use the Flatpak package manager, which is not installed on Ubuntu distributions given Snap, which is Flatpak’s rival, is owned by Canonical and Ubuntu. However, Flatpak is still available to install from Ubuntu’s default repository.

The extra benefit of using Flatpak installations is that you will always have the most up-to-date version compared to Ubuntu which focuses on stability with older versions that only see updates for security issues or serve bugs.

First, install the Flatpak manager; this can be skipped if you already have it installed.

sudo apt install flatpak -y

Next, you need to enable Flatpack using the following command in your terminal:

sudo flatpak remote-add --if-not-exists flathub

For users installing Flatpak for the first time, it is often recommended to reboot your system. Failure to do this can occur with odd issues arising, such as paths not being generated for icons.



Now install using the following flatpak command.

flatpak install flathub org.nomacs.ImageLounge -y

How to Launch Nomacs

Now that you installed the image viewer, launching can be done in two ways.

In your terminal type:


If you want to launch and use the terminal, send it to the background with the following command.

nomacs &

Alternatively, Flatpak users will need to launch using the command below from a terminal instance.

flatpak run org.nomacs.ImageLounge

However, this isn’t practical, and you would use the following path on your desktop to open with the path: Activities > Show Applications > nomacs


How to Install Nomacs on Ubuntu 20.04 LTS

Once open, you will need to select your default language the first time when you open the software, and then you can proceed to use the image viewer.


How to Install Nomacs on Ubuntu 20.04 LTS

How to Update Nomacs

Depending on the method of installation used, the following commands can be used to update.

APT Update Method

sudo apt upgrade && sudo apt upgrade

Flatpak Update Method

flatpak update

How to Remove (Uninstall) Nomacs

Use one of the following commands to suit the original installation method for users who no longer require the application.

APT Remove Method

sudo apt autoremove nomacs -y

Flatpak Remove Method

flatpak uninstall --delete-data org.nomacs.ImageLounge -y

Comments and Conclusion

In the tutorial, you have learned how to install Nomacs on Ubuntu 20.04 LTS desktop.

If you are looking for a powerful yet lightweight image viewer that supports multiple platforms, Nomacs is your program. It is free and open-source, so it won’t cost you anything to download and use it. Its features include thumbnail browsing, comparison viewing, tagging/rating images, slideshows, and much more.


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