The short answer
Usually, after a check. Might hold something you care about. Look inside before removing it.
What is it?
The official Minecraft Launcher stores each Java Edition version it has run, and versions created by mod loaders such as Forge or Fabric, in ~/Library/Application Support/minecraft/versions. Each takes tens to a few hundred MB.
Game versions and mod loaders. The launcher downloads a removed version again when a profile needs it.
What happens if you delete it?
If an installation or profile needs a removed version, the launcher downloads it again. Worlds are stored in the separate saves folder and are not affected.
How to remove it properly
Quit the launcher, delete installations you no longer use in its Installations tab, then move unused version folders to the Trash.
Quit the app that uses it, then move it to the Trash. Empty the Trash when you’re sure.
Before you delete it
Modded versions need their installer (Forge, NeoForge, Fabric) run again, and custom modpack versions may not download again on their own.
How MoreRoom helps
MoreRoom recognises this item and labels it “Review first”: it shows what’s inside, its size and last use, so you can decide. Nothing is removed without your say, and everything goes to the Trash first, with Undo.
Frequently asked questions
Is it safe to delete old Minecraft versions folders?
Usually, after a check. Might hold something you care about. Look inside before removing it. If an installation or profile needs a removed version, the launcher downloads it again. Worlds are stored in the separate saves folder and are not affected.
Will Minecraft game versions come back after I delete it?
Yes. If an installation or profile needs a removed version, the launcher downloads it again. Worlds are stored in the separate saves folder and are not affected.
How do I remove Minecraft game versions properly?
Quit the launcher, delete installations you no longer use in its Installations tab, then move unused version folders to the Trash.