Yoshi’s Island Level Tool exports and imports level data and entrances between any version of Yoshi’s Island (currently U1.0 and J1.0). It is not a level editor: it moves levels from one ROM to another, such as from a romhack to a clean ROM.
What it does
- reads the ROM header and lists all 222 levels with data and sprite pointers, objects, exits, sprites and size
- exports and imports single levels or all of them at once, along with the entrances
- looks for free space in the ROM when importing and updates the level pointers
- clears the data and sprites of the selected levels
- accepts romhacks with custom titles
Patches
The Windows version also applies ASAR patches to the ROM, either the included ones or your own files. The included patches mainly fix issues for SuperUFO flashcart users, such as ArneTheGreat’s Fix GSU Sprite Data Routine, which makes custom sprites work by running the GSU routine from SRAM.
Versions
The first version came out on SMW Central at the end of 2016. Version 1.2, from January 2018, started accepting romhacks with custom titles, updated the gsufix patch and added level icons to the list, and that is when I published the source code on GitHub.
In June 2026 the tool got a web version that runs right in the browser with nothing to install: load the ROM, export or import levels and save the ROM back.
Credits
Thanks to ArneTheGreat, RaidenTheQuick, Lui and all the ASM gods who helped me make this tool.