Setting a custom boot animation on Steam Deck is a bit more involved than just accessing a menu option, as you have to delve into the file structure in desktop mode. But it’s very simple. The gist is that you tweak a setting on the desktop, create two folders and put a .webm file. That’s basically it.
As for the OS version, you don’t have to be in the beta channel. As long as your deck is updated to at least SteamOS 3.3.2, you’re good to go.
Show hidden files in desktop mode
Switch to desktop mode and open an instance of Dolphin. No, not the GameCube/Wii emulator. Dolphin is SteamOS’ file explorer, similar to Windows Explorer or macOS’s Finder.
Click on the sandwich icon at the top right of the window and check “Show hidden files”. (Ctrl+H is also a quick shortcut to achieve this.)
Create the custom animation folder
After enabling hidden files, navigate to ~/.steam/root/config and create a folder called “uioverrides”. Yes, there are two Rs.
Create a Movies folder inside this folder. There you put the custom start video of your choice.
Prepare your video
Custom Steam Deck boot animations require a .webm video, preferably one with a resolution similar to the deck’s 1280×800 screen. If you haven’t already done so, rename the file “deck_startup.webm“. Otherwise the boot animation will not work. Also note that Steam Deck launch videos can be a maximum of 10 seconds.
All that’s left is to restart your deck and enjoy your new animation! If it doesn’t work, check the steps above.
That’s all there is to it. Now that you know like, go ahead and install your own favorite Steam deck boot animation. Beyond thI’ve shared e 16 here, more are appearing every day, so let off steam.