How to Get Started with gThumb on GNOME

gThumb is a GNOME image browser, viewer, organizer, and basic editor. Install it from your distribution’s software source, browse a photo folder, and set it as the default for the image types you choose. Keep GNOME Photos, Loupe, or Shotwell installed if you still use them; removal is unnecessary.

Menu wording and window layouts differ by GNOME and gThumb release, so use the equivalent control if your screen looks different.

Install gThumb

Search your distribution’s software catalog for gthumb and install the package. The GNOME gThumb project page directs users to their distribution’s package manager.

If you prefer a terminal, use the command for your distribution. Review the package manager’s confirmation before allowing it to install the app and its dependencies.

Availability varies by release and enabled repositories. If gThumb is not found, refresh package information and check the official repository configuration. Ubuntu packages it in Universe, which may need to be enabled on a minimal installation. Avoid downloading a package built for a different Linux release.

Open a folder and view photos

1. Launch gThumb

Open Activities, type gThumb, and select the result. You can also find its icon in the app grid. The Super key usually opens Activities, though the layout varies by GNOME version.

2. Browse to a photo folder

Navigate to a folder such as Pictures or one on an attached drive. gThumb displays thumbnails so you can scan the collection without opening each file. If it starts in another location, use the folder navigation or location control to choose a directory. The sidebar can vary by release.

3. Open and inspect an image

Select a thumbnail to open it in the viewer. Use the controls to move between photos, zoom, or switch to full screen. gThumb also offers common file-management tasks in its browser. RAW and newer codec support can vary with the libraries included in your distribution’s build.

Try a simple edit

4. Rotate an image

With a photo open, choose rotate left or right from the viewer controls or menus. Review the result before saving. To preserve the original, use Save As to create a copy when available. Toolbar placement and save prompts vary by version.

5. Crop and save a copy

Choose the crop tool and drag its edges to frame the subject. Reposition and apply the crop, then inspect the result. Because cropping changes the image, use Save As to preserve the source. gThumb also offers basic resizing and color adjustments; use a full photo editor for layered work or advanced retouching. Check the upstream gThumb project for features in your release.

Set gThumb as the default image app

6. Test gThumb on one image

In GNOME Files, right-click an image, choose Open With, and select gThumb. If it is missing, show all applications or choose another application. This opens the file once without changing defaults.

7. Set the default for a file type

To make it stick, right-click a file and choose Properties. Open Open With, select gThumb, and click Set as default. GNOME applies this to files of the same type, not every image format. Repeat with a PNG or another format as needed. See GNOME’s file association help for this method.

Keep other photo apps installed if you use them. A default association controls double-click behavior for that file type; you can still open a file in another app from its context menu.

If gThumb is missing from the app list

Confirm installation, then reopen GNOME Files to refresh its app list. If gThumb works when launched directly but not on double-click, check the default for that exact format; JPEG and PNG can have different associations. For an image error, test a common format and check whether your build supports the file’s codec.