The short answer
Yes. Rebuilt or re-downloaded automatically when needed.
What is it?
Yarn Classic (version 1) stores every package it downloads in ~/Library/Caches/Yarn, shared by all projects so installs can be done offline and faster. Old versions are never removed automatically, so it can grow to several gigabytes.
What happens if you delete it?
Yarn downloads packages again on the next yarn install, which takes longer and needs a connection. Existing node_modules folders keep working.
How to remove it properly
Run yarn cache clean in Terminal, Yarn Classic’s own command (permanent), or move ~/Library/Caches/Yarn to the Trash with Finder’s Go › Go to Folder….
Quit the app that uses it, then move it to the Trash. Empty the Trash when you’re sure.
How MoreRoom helps
MoreRoom recognises this item, shows its real size and when it was last used, and labels it “Safe to remove”. In the free version you can move it to the Trash in one click, with Undo; Pro collects every safe item at once.
Frequently asked questions
Is it safe to delete the Yarn cache on Mac?
Yes. Rebuilt or re-downloaded automatically when needed. Yarn downloads packages again on the next yarn install, which takes longer and needs a connection. Existing node_modules folders keep working.
Will Yarn cache come back after I delete it?
Yes. Yarn downloads packages again on the next yarn install, which takes longer and needs a connection. Existing node_modules folders keep working.
How do I remove Yarn cache properly?
Run yarn cache clean in Terminal, Yarn Classic’s own command (permanent), or move ~/Library/Caches/Yarn to the Trash with Finder’s Go › Go to Folder….