While there is no single "LSD Save Editor" that is universally recognized as the definitive tool, the most prominent software for manipulating save data in LSD: Dream Emulator (PS1) is Lucid Dream Explorer (L.D.E). Lucid Dream Explorer (L.D.E) Review
The phrase "lsd save editor" typically refers to modification tools for the 1998 PlayStation game LSD: Dream Emulator
Have you used the LSD Save Editor to recover a lost file? Share your story in the forums. And always, always make a backup before you edit.
If you are playing the LSD: Dream Emulator (PC Fan Remake), the save files are formatted differently (usually .json or Unity-based save formats) and require a different editor specifically made for the remake version, as original PS1 save editors will not work.