This simple Steam Deck plugin gives me complete control over the UI

For as customizable as the Steam Deck is, it's surprisingly light on UI customization options. You can pick up different start-up animations and change the color of your keyboard — given you've bought designs through the Steam rewards program — but not much beyond that. Thankfully, the community has pushed things further. I've been using the CSS Loader plugin for the better part of two years on my Steam Deck OLED, and it gives me unfettered access to poke, prod, and break the Steam Deck's user interface in any way I see fit.

First thing's first — grab Decky Loader

The plugin loader every Steam Deck owner needs

There's only one plugin loader for the Steam Deck that I'm aware of, and it's called Decky Loader. If you want to expand the functionality of your Steam Deck, you need Decky Loader. Even plugins that aren't available in its marketplace, such as SimpleDeckyTDP, use the Decky Loader framework. Outside of being a way to load your plugins, Decky Loader allows you to install, update, and manage your plugins directly from Game Mode, so you don't need to keep backing out to the desktop when you want to mess around. I'll run you through how to set up Decky Loader here, but if you're already familiar, feel free to skip to the next section.

There are two ways to set Decky Loader up, one faster but more cumbersome, and another longer but easier to parse. Regardless of the method, you'll need to be in Desktop Mode, so go to the power menu on your Steam Deck and switch to the desktop. First, the fast method. If you don't already have a sudo password set up, open up Konsole and enter this command, followed by the password:

passwd

With your password ready to go, open up a new Konsole window and enter the following command, confirming your password after:

curl -L https://github.com/SteamDeckHomebrew/decky-installer/releases/latest/download/install_release.sh | sh

If you can't be bothered with the command line, you can download Decky Loader directly from its GitHub page. Head to the Desktop Mode, open your browser, and go to the GitHub page for Decky Loader. Download the latest release there, navigate to the download location, and drag it to your desktop. Depending on your browser you might see a ".download" tag at the end of the file. Rename the file and remove this tag. The app should be called "decky_installer.desktop" on your desktop.

Run the app and follow the setup process, choosing between the latest stable release or the latest pre-release build. If you have a sudo password set, you'll need to enter it during installation, but if you don't, Decky Loader can automatically set one temporarily for the setup process. And that's it. You can head back to Game Mode once you're done, and you'll see Decky Loader available in the Steam Deck's quick access menu, toward the bottom.

Browse for themes, or build your own

A ton of options, or get your hands dirty with CSS

CSS Loader does exactly what's advertised on the tin. It loads CSS files. If you aren't familiar, CSS stands for Cascading Style Sheet, and it's a file that describes how HTML pages should display on screen. It's the backbone of web design, and it's what enables you to change the UI of the Steam Deck. What's great about CSS is that it just describes how the interface should look. It doesn't change the functionality, so you're able to mess around with one (or multiple) themes through CSS Loader without completely breaking everything on your Steam Deck.

You can install CSS Loader through Decky Loader. Just open the quick access menu, go down to the Decky Loader tab, and select the icon in the top right corner that looks like a marketplace. CSS Loader is available there, and you'll see it among your installed plugins after. Select CSS Loader from the Decky Loader tab, select the install icon in the top right corner, and you can browse the list of available themes. If you don't want to scroll around on your Steam Deck, there's a website where you can browse (and download) the themes, as well.

You'll find a list of the usual suspects. There's a Pip-Boy theme, a Persona 5 theme, themes to make your Steam Deck look like a Nintendo Switch — the list goes on. These are great, but one of the best aspects of CSS Loader is that you're free to install, enable, and configure multiple themes at once. And there are several that only touch a specific aspect of the Steam Deck's interface, giving you more granular control over how everything looks. Here are some of my favorites:

• CapyMenu: A suite of themes for customizing the menus of the Steam Deck, with separate versions for the Steam, quick access, and context menus.
• DellyVolume: Replaces the volume icon with a clean, iPhone-like volume bar.
• BetterBlur: Allows you to adjust the opacity and blur strength for blur effects.
• Fonts: Gives you full control over the fonts used on the Steam Deck, including adding your own.
• No Game Count: Hides the number next to categories in your library; useful if you have a ton of emulated games and non-Steam apps.
• Compact Collections: Collapses Steam collections to make them easier to parse on the Steam Deck.
• Button Prompts Galore: Easily change the button icons used within Steam.
• Art Hero: An extensive homescreen customization theme with a particular focus on showcasing large hero art.
• Obsidian: A great full-system theme alternative that focuses on blacked-out hero art.

Believe it or not, I'm really just scratching the surface here. These are the themes I'd recommend just about anyone install, but you can go so much further. There are themes to tweak the store and download pages, different keyboard themes, and even themes to remove Steam features like review prompts and recent news. They won't all work together — if you have two keyboard themes installed, you can only enable one at a time, for instance — but you're free to turn on or off any of the themes you have installed. Many of the more intensive themes, such as Art Hero, have a ton of additional settings you can tweak in the Decky Loader menu, as well.

If you want to make your own themes, you can, but you'll need some knowledge of how to create CSS themes. For those just getting started, W3 Schools has an extensive library of CSS tutorials with interactive examples. From there, you just need to place the CSS file in the proper folder on your Steam Deck. Make sure to keep the documentation from DeckThemes — the developer of CSS Loader — handy if you want to go through the process yourself.

Two great companion plugins

CSS Loader gets you most of the way there, but these two plugins help

I promised a single plugin to give you complete control of the Steam Deck UI, and CSS Loader delivers exactly that. However, there are two additional plugins you should install if you want to fully customize every aspect of your Steam Deck. The first is SteamGridDB, which is easily my favorite tool available on Steam across both my Deck and desktop. SteamGridDB is a database of official and community-made artwork for games, regardless of if they're on Steam or not. On the desktop, you can apply artwork with a single click via the SGDBoop app. And with the SteamGridDB plugin, you can do the same thing from your Steam Deck.

With the plugin installed, all you need to do is hit the pause button with a game selected and choose Change artwork. You're thrown into the SteamGridDB interface to browse themes for your particular game, and you're given options for box art, hero art, the icon; you get the idea. SteamGridDB isn't exclusive to Steam games, so you can go through the same process with non-Steam apps and emulated games. In addition, SteamGridDB is consistently running a series of projects to create artwork for games or mods that are missing some form of official artwork.

The other plugin you'll want to install is Audio Loader. This is another plugin from DeckThemes that does the same thing as CSS Loader, just for audio. It gives you control over background music and system sounds, and you're free to create your own audio packs — DeckThemes has documentation on how to do that. Different system sounds really sell the idea of customizing your Steam Deck, so I'd recommend playing around with Audio Loader once you have your Steam Deck looking the way you like.

Endless customization

If the only Decky Loader plugin you ever install is CSS Loader, you'll still be left with a near-endless level of customization. CSS is extremely powerful, and it puts you in the driver seat of how your Steam Deck looks and works. SteamGridDB and Audio Loader make for a complete package, but even CSS Loader alone gives you a ton of options.