Save local data are located:
<Your Steam Directory>\userdata\<Your user id>\remote\250900~\.local\share\Steam\steamapps\compatdata\250900\pfx\drive_c\users\steamuser\Documents\My Games\Binding of Isaac RepentanceWhen you load a save file, it will be stored in your browser's local storage. It will not be uploaded to any server.
When you export a save file and paste it in your save folder, you need to go to the stats screen in the game to apply the achievements changes.
If you have any issue, please report it via my X account: Demorck_.
Click the tab you want to modify, then click a button to unlock everything or individual items.
Isaac save editor is an independent project and is not sponsored by, affiliated with or related to the creators or publishers of The Binding of Isaac.
Found how the save file works by projects on github except bestiary, sins, statistics and some others stuffs that I need to understand by myself.
The sprites come from the wiki here.
When the game loads the savefile, it will check marks, endings and stats to unlock achievements.
For example, if you disable all achievements and you have the "Mom" ending, it will unlock corresponding achievements.