Disk Expert is a Mac disk-space visualiser by Nektony that maps your storage into an interactive sunburst chart, letting you drill into folders, identify space hogs, and reclaim gigabytes in minutes.
What is Disk Expert?
Disk Expert is a storage analysis utility for macOS that renders your entire drive — internal SSD, external hard disks, NAS volumes, whatever you mount — as a nested ring chart where each arc is proportional to the space that folder or file consumes. Instead of hunting through Finder column-by-column, you click a ring segment and instantly descend into the biggest offenders. I run it every time my MacBook Pro's available space dips unexpectedly, and it has never failed to surface the culprit in under two minutes.
What does Disk Expert do best?
The sunburst visualisation is genuinely its superpower. Most rivals give you a sortable list — Disk Expert gives you a spatial map that lets your eye do the work. Hovering over any segment pops up the exact file or folder name, its size, and its percentage of the parent. One click zooms in; one right-click opens the item in Finder or moves it to the Trash. The scan itself is fast — a populated 1 TB drive typically resolves in well under a minute on Apple Silicon.
I particularly value the colour-coding by file type: media, caches, application bundles, and document folders each wear their own hue. That alone makes it obvious when an Xcode derived-data folder or a ballooned ~/Library/Application Support directory has quietly eaten half your drive.
- Interactive sunburst — zoom into any folder with a single click
- File-type colour map — instantly see whether video, apps, or caches are the culprit
- Direct Finder integration — reveal or delete items without leaving the chart
- Multi-volume scanning — external drives, SD cards, network shares all supported
- Quick-delete workflow — move items to Trash or delete permanently from within the app
How much does Disk Expert cost?
Disk Expert is free to download from the Mac App Store or from Nektony's website, with a paid Pro upgrade that unlocks full interactive deletion. The free tier lets you scan and explore the chart — which is already more useful than macOS's built-in Storage Management panel — but you will need Pro to move files to the Trash without switching to Finder manually. Given the time it saves on routine storage hygiene, the upgrade is easy to justify for anyone who manages a heavily-used machine.
Who should use Disk Expert?
Any Mac user whose disk has quietly filled up benefits, but power users — developers with sprawling Xcode caches, video editors accumulating render scratch, photographers with duplicate RAW libraries, and sysadmins managing shared Macs — will get the most out of it. If you rely only on Finder's "Get Info" to check folder sizes, Disk Expert feels like switching from a hand trowel to an excavator.
It is less critical if your storage is half-empty or if you already have a workflow with a tool like GrandPerspective or DaisyDisk. But even users who know those apps often keep Disk Expert around as a lighter-weight option for quick checks.
What are the best Disk Expert alternatives?
The two most-compared alternatives are DaisyDisk and GrandPerspective. DaisyDisk is the most polished of the trio — its half-pie layout is visually distinctive and its clean-up assistant is excellent — but it is paid-up-front with no free tier. GrandPerspective renders a treemap (rectangles rather than rings), is open-source and free, but has not received significant UI updates in years and feels noticeably dated on macOS Sequoia. Disk Expert sits in the middle: modern native feel, free entry point, and a sunburst layout that many users find more intuitive than a flat treemap. Apple's own Storage Management (System Settings → General → Storage) is fine for a first pass but cannot drill into arbitrary folders or visualise the whole volume spatially.
How does Disk Expert compare to DaisyDisk?
DaisyDisk wins on visual polish and the guided clean-up basket workflow; Disk Expert wins on price accessibility (meaningful free tier), scan speed on large volumes, and the ability to scan external or network drives without hoops. For a developer who scans often and wants zero friction, I reach for Disk Expert first. For a designer who wants the most beautiful interface, DaisyDisk is the call.
