How To
New to this? No worries. This is the stuff we wish someone had told us the first time we plugged a Quest into a PC. Every bit ends with a link to the official guide, because those stay up to date and the people who make the hardware know it best.
Quest standalone
Turn on Developer Mode
Sideloading needs Developer Mode, and you switch it on from your phone, not the headset. First you'll need a free Meta developer account. It takes a couple of minutes, and you have to verify it before the toggle shows up. Then open the Meta Horizon app, pick your headset, tap Headset Settings, then Developer Mode, and flip it on. Reboot the headset after. If you can't find the toggle, your account probably isn't verified yet.
Meta: device setup and Developer Mode ↗
Install SideQuest and connect your headset
SideQuest is the easy button. Install the desktop app on your PC or Mac and plug the headset in with a USB-C cable that actually carries data. Plenty of charging cables don't, and that trips up everyone at least once. Now put the headset on. You'll see an "Allow USB debugging?" prompt. Tick "Always allow from this computer" and hit Allow. The little dot in the top-left of SideQuest goes green when you're connected.
SideQuest: official setup guide ↗
Install an APK
Most Quest mods come as an APK file. In SideQuest, just drag it onto the window, or use the "Install APK file from folder" button in the top bar. That's genuinely it. If you're comfy with a terminal, adb does the same job:
adb devices
adb install -r yourmod.apkThe first line should list your headset. The -r means "reinstall and keep my data", which is handy for updates.
Android Developers: adb ↗ SideQuest: official setup guide ↗
Where mod files go
Lots of mods need data from the original game sitting next to them, and that part's on you. Two folders matter. Android/obb/<package name>/ is for big data files, and Android/data/<package name>/ is where many apps keep configs, saves and assets. The mod's own page tells you which folder and what the files should be called, so follow it exactly. Launch the mod once first so it creates its folders. Then copy your files over with SideQuest's file manager, with Windows Explorer (the Quest shows up like a phone), or with adb push. And yep, only files from a game you own.
adb push mygamefiles/ /sdcard/Android/obb/com.example.mod/Android Developers: OBB expansion files ↗ Android Developers: adb ↗
Update or uninstall
Updating is just installing the new APK over the old one. Your saves usually survive, but if you care about them, copy the mod's Android/data folder somewhere safe first. To remove a mod, use the trash icon in SideQuest's list of installed apps, or run adb uninstall with the package name. Not sure what it's called? This lists everything you've installed yourself:
adb shell pm list packages -3
adb uninstall com.example.modPCVR
Get SteamVR running
Almost every PCVR mod here runs through SteamVR. It's free on Steam. Install it, connect your headset, and launch it. Do Room Setup the first time so your floor's in the right place. If SteamVR throws an error code at you, Valve keeps a list of what they mean and how to fix them.
SteamVR on Steam ↗ Steam Support: SteamVR troubleshooting ↗
Quest on PC: Link and Air Link
Got a Quest? It doubles as a PC headset. Install the Meta Horizon Link app on your Windows PC and sign in. For a cable, plug in a good USB 3 cable and accept the prompt in the headset. For Air Link, open Quick Settings in the headset, pick Link, and choose your PC. Air Link really wants 5 GHz Wi-Fi, and your PC on Ethernet if you can manage it. Once you're in, launch SteamVR on the PC and you're good.
Meta: set up Link and Air Link ↗
Virtual Desktop
Virtual Desktop is the paid wireless option a lot of folks swear by. Buy it on the Meta Store, install the free Streamer app on your PC from the official site, and sign in to both with the same account. Then connect from the headset. It can launch your SteamVR games for you, too.
Virtual Desktop: official site ↗ Virtual Desktop on the Meta Store ↗
Install a typical PC mod
Most PC mods are a zip you extract into the game's folder, right next to the game's .exe. To find that folder in Steam, right-click the game, then Manage, then Browse local files. In GOG Galaxy it's More, then Manage installation, then Show folder. Extract so the mod's files land beside the .exe, not in a new subfolder. That's the number one mistake, honestly. If there's a readme, read it. It'll tell you if you need a specific game version. Keep a copy of anything you overwrite. If things go sideways, Steam can put the original files back for you.
Steam Support: verify game files ↗
Vortex (Nexus Mods)
Some mods on Nexus Mods are set up for Vortex, their mod manager. Install it and let it find your games. Then hit "Mod Manager Download" on a mod's Files tab, and Vortex works out where everything goes. If it asks you to deploy, say yes. It makes uninstalling painless too.
Your game files, legally
Short version: use your own copy. UnflatVR never hosts or links game files, and we won't point you anywhere that does.
Steam and GOG folders
If you own the PC version, the files you need are already on your drive. In Steam it's Manage, then Browse local files. GOG explains where Galaxy and the offline installers put things.
GOG Support: where is my game installed? ↗ Steam Support: verify game files ↗
Your own discs and cartridges
Some mods want data from a console game. The legit route is making a copy of the disc or cartridge you own with your own hardware. The Dolphin team keeps a proper guide for GameCube and Wii discs. Follow the official guide for your system, and keep the result to yourself.
Troubleshooting
Headset not detected
Nine times out of ten it's the cable. Try another USB-C cable you know carries data, and plug straight into the PC instead of a hub. Then put the headset on and look for the USB debugging prompt. It's easy to miss. Still nothing? Toggle Developer Mode off and on in the phone app and reboot both. On Windows, install Meta's ADB drivers from the device setup page.
Meta: device setup and Developer Mode ↗
Installed it, but it's not in the library
Sideloaded apps don't show up in the main app grid. Open your Library and switch to Unknown Sources. If it's not there either, the install probably failed, so check SideQuest or adb for an error.
Meta: find sideloaded apps (Unknown Sources) ↗
Black screen
Give it a minute first, because an update can look exactly like that. If it's still dark, do a hard reboot: hold power and volume down for about 10 seconds, then pick Boot device. On PC, a black screen over Link usually clears up if you close SteamVR and the Link app, restart Link, then start SteamVR again.
Meta: black screen help ↗ Meta: troubleshoot Link ↗
Performance
Stuttery? Turn things down before you blame the mod. On Quest, a lot of mods have refresh rate and resolution options. 72 Hz is the safe one, and 90 or 120 needs headroom. On PC, SteamVR's settings let you set render resolution per game, so try 100% or a bit lower. Streaming over Air Link or Virtual Desktop? Drop the bitrate a notch and put your PC on Ethernet.
Meta: Air Link Wi-Fi troubleshooting ↗ Steam Support: SteamVR troubleshooting ↗