DaisyDisk: How I Free Up Hard Drive Space on My Mac (Even With Tons of Video Files)

The Library folder on my Mac is 58.1 GB right now. Application Support makes up 35.5 GB of that, and caches add another 14.5 GB.

Finder wouldn't have told me any of that. DaisyDisk did, on one screen.

I've used this app for years. It's the tool I open when my Mac starts feeling tight on space, and it's why I've never been stuck without room to work.

I took the screenshots in this post after clearing out some of the clutter with DaisyDisk.

Why a full Mac becomes a slow Mac

A Mac needs free space to do its own housekeeping. When the drive is nearly full, macOS has less room for temporary files and virtual memory, which means everything gets a little slower. That's how a MacBook Air or MacBook Pro starts to feel old before it actually is.

The bigger problem is updates. A macOS update needs room for the installer plus room to install. If you don't have it, the update fails or never starts. Then you're putting off security patches because of a storage problem you can't see.

So personally, I create a lot of video content, so this hits me faster than most people. Raw footage, exports, project files, and render caches add up quickly. And I have fixed 250GB HD. (I will get a 1TB next time.)

Doesn't macOS already show storage?

It does. The built-in Storage panel gives you categories, and one of them is a vague bucket called System Data. It tells you something is big. It doesn't tell you what.

That's the key gap DaisyDisk fills. It scans a drive or folder and draws it as a circular map. The biggest folders get the biggest slices. You click a slice to drill into it, and the folder path across the top shows where you are.

The cool thing is how fast you find the culprit. Your eye goes straight to the largest slice. A list of file sizes makes you hunt for it.

What I found in my own Library folder

The Library folder is hidden by default on a Mac, so most people never look inside it. That's exactly where the space goes.

Here's the same folder one level down. Application Support alone is 35.5 GB.

Yep, I am a major Claude User. And I'm Claude Code certified.

A few things stand out. One app is holding 13.9 GB. Google is at 4 GB. Descript is at 1.2 GB and Wondershare Filmora is at 416.6 MB, both video tools. None of these are files I'd ever have gone looking for.

You can also see the collector at the bottom left. You drag things you've decided to remove into it, and it keeps a running total. Nothing is deleted until you press the red Delete button.

Why this keeps me productive

Running out of space always happens at a bad time. A render fails halfway. A download won't finish. An update won't install the night before a deadline.

Checking DaisyDisk regularly turns that into a five-minute job instead of an emergency. I look at what has grown, clear what I'm sure about, and get back to work. Which means my Mac stays fast, and I don't lose an afternoon to a storage warning.

It also has a great UI. It's clean, it's quick, and it makes a boring chore oddly satisfying. That matters, because a chore that feels good is one you actually do.

A word of caution before you delete anything

Not everything in that Library folder is safe to remove. Caches are generally low risk because apps rebuild them. Application Support is different. It often holds real app data, settings, and project information.

If you don't recognize a folder, look it up before you delete it. DaisyDisk shows you what's big. Deciding what's safe to remove is still your call.

It works on external drives too

DaisyDisk also scans external drives connected to your Mac. If you keep video files on an external SSD, you can see what's filling it the same way.

Keep in mind, this is a Mac app. There's no Windows version, so if you're on a PC you're out of luck.

You can get it here: DaisyDisk

What to do with the space you free up

Once you know where your storage goes, you can decide what belongs on your Mac and what doesn't. Older projects and finished footage are good candidates to move off the internal drive.

If you need more room, I keep an eye on storage deals here. For cloud storage, I recommend Filen, and you get 10 GB free.

Here's a quick walkthrough of how I use it:

Your next step

Download DaisyDisk, scan your home folder, and look at the three biggest slices. Then tell me what you found. Have you used DaisyDisk, and what was hogging your space?