How to find every node_modules folder and how big it is

The command, piece by piece

• find ~/Projects -name node_modules -type d finds folders named node_modules.
• -prune stops at each match instead of walking into it, so you get one line per project and it finishes in about a second.
• -print0 | xargs -0 keeps folder names with spaces intact.
• du -sh measures each folder; sort -h orders human-readable sizes like 900M and 2.4G correctly.

find ~/Projects -name node_modules -type d -prune -print0 | xargs -0 du -sh | sort -h

How long it takes

On the Mac Sweep was built on, find listed every matching folder in 0.8 seconds, but du took 1 minute 54 seconds to measure them, because node_modules folders hold hundreds of thousands of small files. Measuring several folders at once is much faster: Sweep does the same measurement across all cores in about 18 seconds.

The React Native trap: node_modules that aren't

If you have React Native projects, the list can be inflated. Android's native build cache, android/app/.cxx, mirrors your project's paths, so it contains folders literally named node_modules deep inside, like .cxx/Debug/…/CMakeFiles/…/node_modules. On our Mac, 140 of the 245 "node_modules" that find reported were these mirrors, inflating the list more than twofold. Exclude them:

find ~/Projects -name .cxx -prune -o -name node_modules -type d -prune -print

The .cxx folder itself is safe to delete (Gradle recreates it) and can be hundreds of megabytes.

Other folders worth measuring

node_modules is rarely the only one. On the same Mac: Gradle build + .cxx 34.8 GB, CocoaPods Pods 23.1 GB, Flutter build 18.8 GB, .next 18.5 GB, .dart_tool 8.6 GB.

find ~/Projects \( -name node_modules -o -name Pods -o -name .next -o -name .dart_tool \) -type d -prune -print0 | xargs -0 du -sh | sort -h

Careful with generic names like build, dist or vendor: in some projects they are source. A website template's assets/vendor, for example, is your code.