How to See What Is Taking Up Space in a Folder on a Mac

A folder is 40 GB and you have no idea why. On a Mac the usual answer is Get Info, which confirms the 40 GB and tells you nothing about where it went — or a separate disk-cleaner app, which scans the whole drive to answer a question about one folder.

ComfortFiles answers it where you are already looking. Select a folder with the preview panel open, and the panel measures it and draws what is inside.

What the ring shows

The five biggest things inside the folder, each with its share and its size, and everything else gathered into one line. The total sits in the middle — the same number the Size row gives, because one measurement produces both.

Click any slice and the app goes there. Naming the culprit and then making you go and find it by hand would be stopping half way.

It answers while it counts

Measuring a folder means walking everything inside it, and on a home folder that takes as long as it takes. The ring fills in as the answer arrives, biggest first, so you are reading it while it works rather than watching a spinner. Select something else and the measuring stops — nothing keeps running behind you.

It never quietly under-reports

Some folders cannot be read: another user’s home, parts of the system, anything macOS protects. The obvious thing for a program to do is count those as zero, and the result is a number that is too small — which sends you looking in the wrong place.

Anything unreadable is marked instead. The size is shown as at least that much, and the panel says why underneath.

What it deliberately does not do

It measures one level down, inside the panel, for the folder you selected. It does not scan a drive, build a treemap, or hunt for the one enormous file at the bottom of a deep tree — that is a different product, and a good one, and reaching for it here would mean answering a question nobody asked while making the everyday one harder to reach.

Related

• The preview panel — the panel this lives in, and everything else it shows.
• Sorting by size — the other way to find the heavy things: sort a folder by Size, with folders still on top.

Frequently asked questions

How do I find out what is using space in a folder on a Mac?

Open the preview panel (⇧⌘P) and select the folder. ComfortFiles measures it and draws the biggest things inside as a ring — five of them with their share and size, everything else gathered into one line — and clicking any of them takes you there. Finder can tell you a folder’s total in Get Info, but not where inside it the space went.

Do I need a separate app like DaisyDisk or CleanMyMac?

For this question, no. Those tools scan a whole drive and build a map of it, which is a different job and a good one. This answers the everyday version — “this folder is huge, what is in it?” — in the file manager you already have open, one level at a time, following the folder you are looking at.

Does it scan my whole disk?

No. It measures the folder you selected and stops there. Nothing runs in the background, nothing is indexed, and the moment you select something else the measuring stops with it.

Why does it say “at least” next to a size?

Because something inside could not be read — another user’s folder, or a part of the system macOS protects — and a total that quietly counted those as zero would send you looking in the wrong place. The number shown is a floor, and the panel says so rather than pretending.

Is it slow on a big folder?

It fills in as it counts rather than making you wait for a total, so a folder with thousands of items starts answering immediately and gets more accurate as it goes. Selecting something else abandons the work; nothing keeps running behind you.