Disk Diag Makes Deleting Old Files Easier

I think, if we were to do a random poll, we’d probably find that most of us hate keeping our computers running smoothly more than any other task. Looking for old files and keeping the trash cans empty are unenviable jobs, and as the owner of a small business, I’ve contemplated hiring an all-purpose secretary to handle email and computer maintenance — but that’s not really practical.

All joking aside, one of my favourite things about my Mac are the apps that are available that help make boring tasks like cleaning up my hard drive less dull. Oddly, one of my favourite apps of all time, DaisyDisk, made the task fun. Finding joy in mundane things like computer maintenance is one thing that only Macs can offer, and that’s why I was thrilled to give Disk Diag a shot. It’s a simple app on the Mac App Store meant to do one thing well: clean out your old files. Read on to compare it with some of the competition and see if it’s for you.

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Let’s Talk Design

I start most of my reviews for AppStorm with a little chat about the design principles of any given app, and I don’t think that’s entirely unwarranted. But in the case of an app like this, I think it matters even more than usual. If an app like this is ugly, I’m never going to bother using it.

The app looks odd, but it feels very friendly in use.

The app looks odd, but it feels very friendly in use.

That’s why I wanted to spend a few minutes talking about the charm of Disk Diag. Its most obvious visual comparison is a speedometer, which threw me off for a couple seconds. My main thought is that the app works really quickly, so I suppose a speedometer is a relevant metaphor. But it seems odd.

In fact, the app sort of looks odd in screenshots. To be completely frank, you have to try this app to understand its charms. The joy is in the animations. The Start button pulses on occasion, but never loses its friendly veneer.

The list of everything Disk Diag found for me to delete.

The list of everything Disk Diag found for me to delete.

Hitting Start brings up a quick list of different folders you could delete. Most of these are caches, the Trash can, or Mail downloads (the first time I deleted my Mail downloads, I had over a gigabyte sitting in there that I had simply never bothered to check out — and I’ve only been using this specific Mac for a year).

When you choose to wipe everything clean, a friendly dialogue bubble will let you know that you should back up your hard drive first (just in case). Deleting everything happens relatively quickly, and as it does, the speedometer dial acts as the visual completion reference. That’s when the metaphor becomes very cool.

And we're done.

And we’re done.

And that’s it. This is a really basic app, but it gets the job done for a number of basic users. For people new to Mac, or people like my mother who would never download an app like DaisyDisk for fear of damaging something, it’s an easy recommendation.

But should you use it?

The Alternatives

There aren’t a ton of free alternatives. If you don’t mind paying for it, Clean My Mac 2 is a much more comprehensive solution. Again, DaisyDisk is an excellent piece of software. OmniDiskSweeper, available for free from the always-reputable OmniGroup, is available for free from their website. That being said, it’s not as dummy proof. Like the description says, “Delete away, but exercise caution.”

Disk Diag and DaisyDisk side by side.

Disk Diag and DaisyDisk side by side.

Of course, the other option is to delete everything yourself or use something like Hazel to automate when you delete things. If you take the time to set it up, Hazel can clear out caches or the trash can on a schedule (and it will boot when you log in). But Hazel is $28 USD — it’s a far cry from free, but for good reason. After all, it’s a comprehensive solution for Mac pros who need to enhance their workflows, not just empty their trashcans.

Theoretically speaking, you could also remove files or directories using Terminal (and if you’re interested, here’s some geekery about just that). But the problems with that are manyfold: most of us dn’t have time to punch in a bunch of code for each individual directory, and for anybody other than the most advanced of Mac users, the probability of making huge mistakes is going to be much higher. Even if you do know what you’re doing with Terminal, it’s time-consuming.

Final Thoughts: A Warning About Sandboxing

That being said, I’m also slightly curious about how effective Disk Diag is. I’m not an expert on the sandboxing that the Mac App Store has brought with it, so I’m relying on you folks to correct me if I’m wrong, but my understanding is that an app doesn’t have access to the whole hard drive. So while an app like Disk Diag is convenient for novices and power users alike, it’s not necessarily going to clean up everything hogging up your hard drive.

But I’m not sure what is. After doing some research and reading up on the options, the only thing I know is simply this: if you want to really clean up all the useless files on your Mac, you’re going to have to know OS X pretty well. And you’re probably going to have to repeat some of the process every time a new OS is released. It’s a giant pain. For me, Disk Diag makes it easy. I have my concerns about the simple deletion that a Mac App Store app could be doing, but at the same time, it makes it so simple that I find very little reason to complain. At a nonexistent price point, Disk Diag is practically a must-have for busy people.


Disk Diag makes deleting old files and purging ones that are taking up space on your hard drive easier, but I'm not sure we'll ever find a perfect solution.