adw-gtk3: porting libadwaita's look to GTK3 applications in GNOME

adw-gtk3 fills the visual gap between legacy GTK3 apps and libadwaita's GTK4 look

GNOME desktops that use libadwaita for GTK4 applications create a visible inconsistency when GTK3 apps still render with the old Adwaita styling. adw-gtk3 addresses this by porting libadwaita's CSS to GTK3, so legacy applications adopt a look closer to what GTK4 apps produce.

It is distributed under LGPL-2.1. Nine repository topics (adw-gtk3, adwaita, gnome, gtk-theme, gtk3, gtk3-theme, libadwaita, linux, theme) reflect the project's focused scope: this is a GNOME desktop GTK3 theme, not a general Linux desktop theme.

The README is explicit about one boundary: "This port does not claim to be a 100% look-a-like of libadwaita. There are some limitations to what GTK3 can do." Users who expect pixel-perfect parity with libadwaita will find gaps, particularly in widgets or effects that have no GTK3 equivalent. adw-gtk3 closes the most visible inconsistencies, not all of them.

Written in SCSS and built with Meson: how the GTK3 CSS theme is structured

SCSS is the primary language, a CSS preprocessor that compiles down to plain CSS files GTK3 can read as a theme. Source lives under src/, which has its own README.md for contributors who want to build from source. At the repository root, meson.build drives the installation, placing compiled CSS in the correct system or user directories.

Of the 11 top-level entries (.gitattributes, .github/, .gitignore, LICENSE, README.md, images/, meson.build, scripts/, snap/, src/, version), the version file is notable: it holds the current version string separately from any tag or meson.build constant, which is an uncommon layout for a theme project. Pre-built packages handle the SCSS compilation and Meson installation for most users, so the build toolchain is only relevant for contributors or those building from source.

Installing via Fedora, Arch, Manjaro and other distribution packages

For Fedora, Arch and Manjaro, the README gives package manager commands. On Fedora:

dnf install adw-gtk3-theme

On Arch:

pacman -S adw-gtk-theme

On Manjaro:

pamac install adw-gtk3

Note the package name difference: Fedora uses `adw-gtk3-theme`, Arch uses `adw-gtk-theme` (no trailing digit), and Manjaro uses `adw-gtk3`. Getting the name wrong returns a package-not-found error. Debian users are directed to a third-party repository.

A tarball download from the releases page is also available: extract its contents to `~/.local/share/themes/` for a user-level install that does not require root. Snap users can install the theme Snap with:

sudo snap install gtk-theme-adw-gtk3

After installing, activate the theme in gnome-tweaks under Appearance > Legacy Applications. For dark themes, switch the color scheme in gnome-control-center > Appearance.

Switching between light and dark modes with gsettings and the GTK4 dark theme fix

gnome-tweaks is the graphical route, but gsettings works from the terminal and is scriptable. To activate the light theme:

gsettings set org.gnome.desktop.interface gtk-theme 'adw-gtk3' && gsettings set org.gnome.desktop.interface color-scheme 'default'

For dark mode:

gsettings set org.gnome.desktop.interface gtk-theme 'adw-gtk3-dark' && gsettings set org.gnome.desktop.interface color-scheme 'prefer-dark'

To revert to the system default:

gsettings set org.gnome.desktop.interface gtk-theme 'Adwaita' && gsettings set org.gnome.desktop.interface color-scheme 'default'

If dark mode still does not apply to some GTK4 apps after switching, the README gives a fallback: add these 2 lines to `~/.config/gtk-4.0/settings.ini` and then relog:

[Settings]
gtk-application-prefer-dark-theme=1
gtk-theme-name=adw-gtk3-dark

The relog step is easy to miss. Without it, some apps may ignore the settings.ini change.

Flatpak apps need a separate installation path, and the 2 options have different trade-offs

Flatpak sandboxing prevents apps from reading the host theme by default, so installing adw-gtk3 on the host alone does nothing for Flatpak apps. Two installation paths address this.

Installing from Flathub is simpler:

flatpak install org.gtk.Gtk3theme.adw-gtk3 org.gtk.Gtk3theme.adw-gtk3-dark

However, the README adds a constraint: the Flathub version does not work with non-libadwaita GTK4 apps. For a mix of GTK3, libadwaita GTK4 and non-libadwaita GTK4 apps, the flatpak override approach is needed instead:

sudo flatpak override --filesystem=xdg-data/themes
sudo flatpak mask org.gtk.Gtk3theme.adw-gtk3
sudo flatpak mask org.gtk.Gtk3theme.adw-gtk3-dark

This override approach requires the theme to also be present in `~/.local/share/themes`, meaning the tarball install is a prerequisite. The 2 flatpak mask commands prevent the Flathub theme packages from overriding the local copy. Choosing the wrong option here means some apps still render with their default styling.

What adw-gtk3 cannot replicate: the GTK3 ceiling

GTK3 and GTK4 share a stylesheet model but GTK4 supports newer CSS properties, widgets and drawing primitives that GTK3 does not. adw-gtk3's SCSS theme works within GTK3's subset of CSS support, so any libadwaita widget that depends on GTK4-only features has no equivalent. How visible this gap is depends on which apps are running: apps that use only standard GTK3 widgets benefit fully, while apps that do unusual things with custom drawing or non-standard widgets may not benefit at all.

There is also no guarantee that a future GNOME update to libadwaita will be immediately reflected in adw-gtk3. Package maintainers for Fedora, Arch and other distributions are listed separately in the credits section, which means package freshness depends on each contributor's cadence rather than on the upstream repository alone.

11 companion projects for applications outside the GTK3 scope

adw-gtk3 covers GTK3 apps; the README's related projects table lists 11 separate ports for other application frameworks and environments. GTK2 is covered by adw-gtk2-colorizer. Gimp 3 has adw-gimp3. KDE has a Libadwaita-KDE port and a Kvantum variant. adw-colors provides accent color customization for GNOME 47 and later through a CLI program.

For browser-based and Electron-style apps, separate theme projects exist for Firefox (firefox-gnome-theme), Thunderbird (thunderbird-gnome-theme), VSCode (vscode-adwaita), Discord (discord-gnome-theme) and Obsidian (obsidian-adwaita-theme). Steam has Adwaita-for-Steam. Window decoration for xfwm4 is handled by adw-xfwm4.

These projects are independent. adw-gtk3 does not bundle or manage them, and none of the 11 companion projects are listed as dependencies. Anyone who wants a fully unified libadwaita look across all desktop surfaces needs to install and update each one separately.

Editorial conclusion

adw-gtk3 is worth installing if your GNOME desktop mixes GTK3 and GTK4 libadwaita apps and the visual gap is noticeable. GTK3 apps pick up the theme once it is active; Flatpak and Snap apps require additional steps, and the Flatpak Flathub option excludes non-libadwaita GTK4 apps. Before activating, confirm your package is current: v6.5, published on 2026-04-13, is the latest version. On a non-GNOME desktop the theme's reach is unpredictable. To undo the change, the gsettings revert command returns the desktop to the default Adwaita theme without rebooting.

Frequently asked questions

Official sources

1. Issues
2. lassekongo83/adw-gtk3 on GitHub
3. License: LGPL-2.1
4. README
5. Releases