Games you load are kept on this device so you can jump back in. Your ROM files never leave your browser. Progress is saved automatically — use Export .sav to back it up elsewhere.
Save your progress to a numbered slot, or load any saved state. Auto-save keeps a rolling backup every couple of seconds for crash recovery — use a numbered slot for saves you want to keep.
Enter a Game Genie (ABC-DEF-GHI) or GameShark (8 hex, e.g.
019950C0) code. Saved per game on this device.
Your ROM file is opened read-only and is never modified. When a game saves, the save data goes into this browser's private storage (browser storage), keyed by the ROM's file name. That is why your progress is still there when you reopen the page.
Export .sav downloads the native save file — the same format real hardware and other emulators (mGBA, RetroArch, flash carts) use. That downloaded file is the copy that is genuinely yours. Import .sav loads it back, here or anywhere else.
Export the .sav on the old device, then load the same ROM on the new one and import it.
Do this before you clear your browser data or reinstall.
Saves are matched by ROM file name — renaming the ROM hides its save. Opening the page from a file on disk and from a web address counts as two separate storages. Private/incognito windows discard everything on close.
No controller detected. Connect one and press any button.
Most gamepads (Xbox, PlayStation, Switch Pro, 8BitDo, Steam Deck's built-in controls) are recognised automatically. If a button is wrong, press Rebind next to it and then press the button you want. Triggers fast-forward. Your mapping is remembered per controller.