Pokémon LeafGreen
Boots, lightly testedGame Boy Advance · 2004 · RPG · Decompilation
Return to Kanto: catch, train and battle through the original 151.
Controls
| Arrow keys | D-pad |
| Z | A |
| X | B |
| A / S | L / R |
| Enter | Start |
| Shift | Select |
| Gamepad | any standard controller (untested) |
About this build
Pokémon LeafGreen built from the pret/pokefirered decompilation, pinned at 037335f4. The build is byte-identical to a retail (USA, Europe) (Rev 1) cartridge dump — sha1 7862c67bdecbe21d1d69ce082ce34327e1c6ed5e — and runs in the browser on a direct WebAssembly build of mGBA's core, with no emulator frontend in between. You supply your own ROM: it is read in your browser with the File API, checked against the hashes the decompilation documents, and handed straight to the emulator. The page is static files with no server, and its Content-Security-Policy sets connect-src 'none', so the browser itself refuses to let the page make any network request at all.
- Built from
- the pret/pokefirered decompilation, built to a matching ROM and run on a direct WebAssembly build of mGBA's core
- Type
- Decompilation
- Game files
- Your own Pokémon LeafGreen ROM (USA, Europe) (Rev 1), sha1 7862c67bdecbe21d1d69ce082ce34327e1c6ed5e. It is read in your browser and never uploaded.
- Code licence
- pret/pokefirered; mGBA core MPL-2.0
- Assets
- None distributed — the player supplies their own ROM
- Source
- andrewnakas/pokeleafgreen-web ↗
What has been tested
Byte-identical build verified by cmp against a retail dump and reproduced from a clean tree. Muted headless run: ROM read in-page (sha1 match), CSP connect-src 'none' proven by five refused egress attempts and corroborated at the network layer, core boots, and the game's own gMain.callback2 walks title -> main menu -> naming -> overworld with sLockFieldControls clear and the player walking on the game's own tile grid. A save made from the game's SAVE menu survives a reload: the game reports SAVE_STATUS_OK and continues onto the exact saved tile. No play-testing beyond the first room.
Last tested 2026-10-05 in Chrome 151 (headless, software GL). Full playthrough: not verified. How games are tested.
Known limitations
- You must supply your own ROM; none is distributed.
- Revision 1 only — the rev 0 and Switch Online dumps are a different build and are untested here.
- FireRed is not accepted by this page, only LeafGreen.
- Verified as far as the bedroom in Pallet Town, walking, and an in-game save that survives a reload. Battles, the wider overworld and the rest of the game have not been play-tested.
- Sound is implemented but has never been listened to — all testing was muted.
- Keyboard and gamepad only; there are no on-screen touch controls, so phones and tablets are not usable.
- Tested in headless Chrome 151 only, with software rendering.
- Link cable, trading and link battles are not available in the browser.
Saves
Save from the in-game menu (Start, SAVE). The cartridge save is mirrored into this browser's storage and restored automatically on reload, so the game offers CONTINUE when you come back. There are also save-state buttons. Clearing site data removes everything, including the cached ROM.
