DaisyDisk shows you the disk. It will not tell you what is safe to delete

DaisyDisk is a good piece of software. The sunburst map is the fastest way I know to see where a disk went, it costs $9.99 once, and it has been around long enough to trust. This is not a page arguing against it.

It is a page about the question DaisyDisk stops at.

The map ends at a folder name

Scan a developer's Mac with DaisyDisk and the map shows a fat wedge for ~/Library, inside it Developer, inside that CoreSimulator and Xcode, inside those Devices, DerivedData, iOS DeviceSupport, Archives. Correct and useful.

Then you have to decide. Is iOS DeviceSupport safe? What happens if I delete Archives? Is the 9 GB in Containers/com.docker.docker the Docker VM or its cache? DaisyDisk's answer is the folder name and the size. The one-star reviews on its App Store page are all versions of "it showed me 360 GB of system and could not tell me what to do about it".

That is the right complaint. It is also outside what a visualiser is for.

What Decruft does with the same folders

Decruft starts from a list of locations it knows, not from the whole disk. For each one it shows the path, the size, the age, and a sentence on what recreates it:

• DerivedData: Xcode rebuilds it. Safe.
• iOS DeviceSupport: re-downloads when you attach a device. Safe.
• Archives: carries the dSYM that symbolicates crashes from that build. Review first.
• iPhone backups: may be the last copy of a phone you no longer have. Review first.
• Containers/com.apple.mail: your mail. Refused.

You tick rows. Everything ticked goes to the Trash, not straight to deletion. Anything the guard does not recognise is never offered.

Where DaisyDisk is still the better tool

Anything outside the known locations. A 40 GB video export in a folder you forgot, a bloated ~/Downloads, a project with a 12 GB .git. Decruft's Large Files pane sorts a folder by size, but the sunburst is a better way to find the surprise you did not know to look for. Many people run both: the map to find the wedge, the list to decide what in it is safe.

Price

DaisyDisk: $9.99 once, up to 5 Macs. Decruft: $19 once, up to 3 Macs. Scanning is free without a license, so the list of what it found, with the safe and review-first labels, costs nothing to read.