How to Install PS2 BIOS
Installing a PS2 BIOS means putting the file in your emulator's bios folder and selecting it. On Windows that folder is Documents\PCSX2\bios. On phones and Steam Deck the app imports the file for you. Extract the file first, and never nest it inside a subfolder.
Below is how to install PS2 BIOS on every common emulator, one platform at a time. The exact spot depends on your device, so pick your platform below. First you need the BIOS file, from a verified download or your own dump, and which PS2 BIOS to use helps you pick the region.
What you need before you install
The BIOS file itself, extracted, and its region. That is the whole checklist.
Get the file first. Dumping your own is the clean route, and our dump guide covers it. If you use a ready file instead, unzip it and keep its original name. Once the file is in hand, the install is the quick part.
Emulator first, then BIOS
Install the emulator before the BIOS, because the emulator creates the folder the BIOS goes into.
On desktop, opening PCSX2 once creates the Documents\PCSX2\bios folder. On Android and Steam Deck, install the app or EmuDeck first for the same reason. Then add the BIOS using the steps for your platform.
Two rules that prevent most problems
Extract the file, and do not nest it. Almost every "BIOS not detected" case breaks one of these.
- Extract the
.binfrom any.zipor.7z. Emulators cannot read an archive. - Put the file directly in the
biosfolder, not in a folder inside it. - Keep the original file name. The name helps the emulator identify the BIOS.
The first-time setup shortcut
The easiest moment to install the BIOS is the first time you open the emulator.
Fresh PCSX2 and the Android apps run a short setup on first launch, and one step asks for your BIOS. Point it at your file there and you are done. If you closed that setup or configured things earlier, you can add the BIOS later from the emulator's BIOS settings, as shown per platform below.
Where the BIOS goes on each platform
Every emulator has one place it looks for the BIOS. Find yours below.
Install on Windows (PCSX2)
Put the file in Documents\PCSX2\bios, then select it in the emulator.
- Extract your BIOS file so you have the raw
.bin. - Open
Documents\PCSX2\bios. If it is not there yet, open PCSX2 once and it will create the folder. - Copy the
.binand any companion files into that folder. - In PCSX2, open Settings > BIOS, click Refresh List, and select your BIOS.
On the BIOS screen you can also use the Open in Explorer button to jump straight to the correct folder.
Install on macOS (PCSX2)
Open the BIOS folder from inside PCSX2, drop the file in, and refresh.
On macOS the folder sits inside your user Library, so the in-app button is the easiest route. In PCSX2, open Settings > BIOS, use the folder button to open the bios folder, copy your file in, then click Refresh List and select it. This saves you from digging through hidden Library folders.
Install on Linux (PCSX2)
Use the in-app folder button, then refresh.
The folder lives under your user config directory, and the Flatpak build keeps it inside its own sandbox. So in PCSX2, open Settings > BIOS, use the folder button to open the bios directory, copy your file in, click Refresh List, and select it. You can also point PCSX2 at any folder with Browse.
Install on Android (NetherSX2, AetherSX2, PCSX2)
Use the app's built-in BIOS import. It copies the file into place for you.
On first launch these apps ask for the BIOS. Tap the BIOS step, browse to your file, and the app imports it. If you skipped that, open the app's Settings and find the BIOS or System section to add it. You do not move files by hand on Android. Note that AetherSX2 is no longer updated, so NetherSX2 is the better pick today. The full walkthrough is on the PS2 BIOS for Android page.
Install on Steam Deck (EmuDeck)
Put the file in the Emulation/bios folder, then run the EmuDeck checker.
EmuDeck keeps every BIOS in one place at Emulation/bios in your home folder. In Desktop Mode, copy your .bin there. Then open EmuDeck and run its BIOS Checker to confirm the file is found and valid. That single folder covers both PCSX2 and RetroArch on the Deck.
Install in RetroArch (LRPS2 core)
Put the file in system/pcsx2/bios, with lowercase folder names.
RetroArch reads BIOS files from its system folder. Inside it, create pcsx2/bios, so the full path is system/pcsx2/bios, and place your file there. On a case-sensitive system, keep pcsx2 and bios in lowercase. If you are unsure where system is, check Settings > Directory > System/BIOS in RetroArch.
Install on iOS
iOS apps either import the BIOS in-app or read it from RetroArch's system folder.
For RetroArch on iOS, add the file to system/pcsx2/bios through the Files app. For ARMSX2, use its in-app BIOS import. Play! needs no BIOS at all, because it has one built in. Which iOS app suits you is covered on the best PS2 emulator page.
After you install: pick the right region
Select the BIOS that matches your games.
Once the file is detected, most emulators list each BIOS by region. Choose the one for your library, which is usually the USA BIOS for English games. The which PS2 BIOS to use guide covers the rest.
Installing more than one BIOS
You can keep several BIOS files at once and switch between them.
Drop every BIOS you have into the same bios folder. The emulator lists them all, and you pick whichever region a game needs, with no reinstall. This helps if your library mixes USA, Japanese, and PAL titles.
How to know it worked
You will see the BIOS listed in the emulator, and a game will boot past the PlayStation 2 logo.
After you refresh the list, the BIOS shows up by region. Load any game and it should start with the PS2 boot animation instead of a "BIOS not found" message. That animation is the sign the BIOS is installed and working. That is all there is to how to install PS2 BIOS: place the file, refresh, and pick your region.
If your BIOS is not detected
Almost always it is zipped, nested in a subfolder, or renamed.
Extract it, move it directly into the bios folder, keep its original name, then refresh the list. If it still does not show up, the BIOS not found fix page walks through every cause. You can also confirm the file is genuine with a checksum, which the PS2 BIOS files explained page shows.
Frequently asked questions
Where do I put the PS2 BIOS on Windows?
Documents\PCSX2\bios. Then open Settings > BIOS in PCSX2, click Refresh List, and select it.
Do I need to unzip the BIOS first?
.bin before you install it. Emulators cannot read a zipped file, so a still-zipped BIOS will not be found.
Can the BIOS go in a subfolder?
bios folder. A file nested inside another folder will not be detected.
How do I install the PS2 BIOS on Android?
Where does the BIOS go in RetroArch?
system/pcsx2/bios, all lowercase. If you cannot find the system folder, check Settings > Directory > System/BIOS in RetroArch.