# How to have thumbnails in file dialogs in certain GTK applications

*Note: The GTK file chooser
[got thumbnail support](https://thisweek.gnome.org/posts/2022/12/twig-74/)
in version 4.10.*

You can have large thumbnails in the file chooser in certain GTK 3 applications. Only a minority of applications supports this feature, but this minority includes Firefox and Thunderbird. The trick, surprisingly, is to force GTK applications to use KDE dialogs. You don't need to use KDE itself, and the instructions assume you don't.

## Instructions

The following instructions have been tested in Ubuntu 20.04. It should be possible to use them in other Linux distributions with small adjustments.

### Install the required packages

```sh
sudo apt install kio-extras xdg-desktop-portal-kde
```

### Enable the KDE file chooser

```sh
sudo sed -i "s/\(UseIn=.*\)/\1;$XDG_CURRENT_DESKTOP/" /usr/share/xdg-desktop-portal/portals/kde.portal
echo GTK_USE_PORTAL=1 >> ~/.pam_environment
```

### Log out and log back in

Done.

## Sources

- [Replace GTK+ file dialog with alternative](https://superuser.com/questions/944119/replace-gtk-file-dialog-with-alternative)
- [Dolphin not showing preview of images or any files](https://askubuntu.com/questions/813711/kde-dolphin-dolphin-not-showing-preview-of-images-or-any-files)
- [`GtkFileChooserNative`](https://docs.gtk.org/gtk3/class.FileChooserNative.html)---GTK Documentation

## Page metadata

URL: <https://dbohdan.com/gtk-dialog-thumbnails.md>

Published 2020-12-21, updated 2024-02-20.

Tags:

- how-to
- Linux
- personal computing