Mac Disk Space Analyzer: DaisyDisk vs GrandPerspective vs OmniDiskSweeper
Mac Disk Space Analyzer: Which One to Use and How to Read It
The best Mac disk space analyzer for most people is DaisyDisk ($9.99, one-time). The best free one is GrandPerspective for a visual map, or OmniDiskSweeper for a plain list sorted by size. Before installing anything, macOS's own Storage settings will tell you which category is the problem.
All of them answer one question: which folders are actually eating my disk? They differ in how they draw the answer, what they can see, and whether they explain the gray "System Data" blob. This page compares them and then covers the part most reviews skip: what to do with what they find.
If you just want a cleanup checklist, that lives in how to free up space on Mac. This page is about picking the tool.
Mac Disk Space Analyzer Comparison
Prices and versions checked on the developers' sites in October 2026.
| Tool | Price | Visualization | Current requirements | Best for |
|---|---|---|---|---|
| DaisyDisk | $9.99 one-time (direct or Mac App Store) | Sunburst (concentric rings) | macOS 10.13+ direct, 12+ App Store; Apple silicon and Intel | Most people; explaining hidden and purgeable space |
| GrandPerspective | Free (SourceForge), $2.99 (App Store) | Treemap (rectangles) | macOS 14+ for the latest release; Apple silicon and Intel | Free visual scan; seeing every file at once |
| OmniDiskSweeper | Free | Sorted list, column view | Version 1.16, Apple silicon native | Fast "what is biggest" answer with no charts |
| Disk Space Analyzer: Inspector (Nektony) | Free; Pro is $4.99/mo, $9.99/yr or $19.99 lifetime | Sunburst | macOS 11+ | Free sunburst view if you do not mind upsells |
| macOS Storage settings | Built in | Category bar + lists | macOS Ventura and later | First check; large documents and iOS backups |
Finder / Terminal (du) | Built in | Text | Any macOS | Quick folder sizes without installing anything |
What all third-party analyzers share: they only see what macOS lets them read. Without Full Disk Access, every one of them under-reports. More on that below.
DaisyDisk: The Best Paid Mac Disk Space Analyzer
DaisyDisk draws your disk as colored rings. The center is the drive, each ring outward is a deeper folder level, and a slice's width is its size. Click a slice to zoom in. Large problems look large, which is the whole point.
Price: $9.99 for a lifetime license, no subscription. The direct license covers up to 5 personal Macs, and there is a free download to try it first. It is also on the Mac App Store for the same $9.99.
Requirements: the direct version needs macOS 10.13 or newer; the App Store listing requires macOS 12. Both run on Apple silicon and Intel. The current release is 4.34.2 (July 2026).
What sets it apart is hidden space. When the files DaisyDisk can scan do not add up to your disk's used space, it shows the leftover as a single "hidden space" item and breaks it into:
- Purgeable space — mostly local Time Machine snapshots, plus swap files, sleep images, and caches macOS can drop on demand
- Other volumes in the same APFS container
- Still hidden — other users' home folders, protected system data, file system overhead
Scanning as administrator, or granting Full Disk Access, shrinks the hidden item and makes protected folders appear in the map.
Direct vs App Store matters here. DaisyDisk can force macOS to purge purgeable space when you drag that item to its Collector, but its own documentation says this feature is not available in the Mac App Store edition. Buy direct if you want it.
You delete by dragging items to the Collector at the bottom, then confirming. Nothing is removed until you do.
Downsides: it costs money, and the sunburst can be hard to read when you have thousands of small files in one folder (a Photos library looks like one solid slice).
GrandPerspective: The Best Free Disk Space Analyzer for Mac
GrandPerspective draws a treemap: every file is a rectangle sized in proportion to its bytes, and files in the same folder are grouped together. You see the whole disk at once, so a single 40 GB video file jumps out as one huge block.
Price: free and open source from SourceForge. The Mac App Store version costs $2.99. The developer says it is the same app; paying gets you App Store updates and funds development.
Requirements: version 3.8.1 (September 2026) needs macOS 14 or later on Apple silicon or Intel. Older releases remain available for older macOS versions.
Notable features:
- Color files by type, extension, folder, size, or date — coloring by type instantly shows how much of the disk is video
- Filters to exclude or mask items during a scan
- Time Machine hard-link analysis and support for cloud files
- Save a scan and reload it later, or export it as an image or text
- Quick Look, Reveal in Finder, and delete from the view
Downsides: the interface is functional rather than pretty, and a treemap does not show folder hierarchy as clearly as DaisyDisk's rings. It also does not explain purgeable or hidden space; it just shows what it could scan.
OmniDiskSweeper: The Simplest Free Option
OmniDiskSweeper from The Omni Group has no visualization at all. It shows each folder with its size, sorted largest first, in a column view like Finder. Click the biggest folder, then the biggest folder inside it, and keep going until you hit the actual files.
Price: free. It has been freeware since 2009.
Requirements: the current download is version 1.16 (September 2025), distributed for macOS 11 and later, and it runs natively on Apple silicon.
Why pick it: for many people a sorted list is faster than any chart. You are looking for the top three items, and a list puts them at the top. It also has a delete button. Use it carefully: it will happily remove things you should not, so double-check anything outside your own folders.
Downsides: no graphics, no explanation of hidden or purgeable space, and the interface has barely changed in years.
Other Tools Worth Knowing About
Disk Space Analyzer: Inspector (Nektony) is free on the Mac App Store with a sunburst view similar to DaisyDisk's. The free tier scans, navigates, and shows the biggest items; removing files and the full sorted lists sit behind Pro ($4.99/month, $9.99/year, or $19.99 lifetime). Fine if you want a free sunburst, but a one-time $9.99 DaisyDisk license is cheaper than a year of Pro.
Disk Inventory X still appears in a lot of older roundups. Its last release, 1.3, lists support for macOS 10.13 to 10.15 only. Skip it on a current Mac; GrandPerspective uses the same treemap idea and is maintained.
Many "best disk analyzer" lists are published by companies selling cleanup suites. Those suites can scan disks too, but they bundle cleaning, uninstalling, and subscriptions. If all you need is to see what is big, a dedicated analyzer is cheaper and does less behind your back.
Built-In Options: No Download Needed
System Settings → Storage
Apple menu → System Settings → General → Storage (macOS Ventura and later; on Monterey and earlier it is About This Mac → Storage). Wait for the bar to finish calculating, then click the info (i) button next to a category.
This is the best first step because it answers which kind of data is the problem. Documents → Large Files sorts your biggest files, and the iOS Files section lists old iPhone backups. What it does not do is show a folder map, and System Data is a single number with no breakdown. Our guide to clearing System Data explains that gray bar in detail.
Finder
Open a folder, switch to List view, choose View → Show View Options, and tick Calculate all sizes. Then click the Size column to sort. Slow on big folders, but it works anywhere.
Terminal
Size of one folder:
du -sh ~/Movies
Every folder one level down, sorted smallest to largest (so the biggest are at the bottom):
du -h -d 1 ~ 2>/dev/null | sort -h
Run it on your home folder first. If Terminal does not have Full Disk Access, some folders will be skipped or under-counted, the same limitation third-party apps have.
How to Read Disk Analyzer Results
Every Mac disk space analyzer will show you a big picture. Interpreting it is where people go wrong.
1. Grant Full Disk Access before you trust the numbers. Go to System Settings → Privacy & Security → Full Disk Access and enable the analyzer, then rescan. Without it, Mail, Messages, Safari data, and parts of ~/Library are invisible and the totals will not match macOS.
2. A gap between the analyzer and macOS is normal. A few gigabytes of unexplained space is file system overhead and protected system files. Tens of gigabytes usually means local Time Machine snapshots, which no analyzer can browse as folders. DaisyDisk labels these as purgeable; the others simply leave them out. The fix is in the System Data guide.
3. Purgeable space is not a problem to solve. It is space macOS will hand back when an app needs it. Finder counts it as available. Deleting files while Time Machine is on can even make purgeable space grow temporarily.
4. Know which big folders are safe to touch. Usually worth investigating:
~/Movies— iMovie and Final Cut Pro libraries, exports, and render files~/Pictures— the Photos library, as one large package~/Desktopand~/Downloads— screen recordings save to the Desktop by default~/Library/Application Support/MobileSync/Backup— old iPhone and iPad backups~/Library/Caches— rebuildable, but clearing it gains little long-term
Leave /System, /private/var, and anything you do not recognize under /Library alone. For the step-by-step cleanup of each of these, use how to clean up a Mac hard drive rather than deleting from inside the analyzer.
What the Map Usually Shows: Video
Run any of these tools on a typical personal Mac and the largest blocks are rarely apps or system files. They are video:
- Screen recordings captured at Retina resolution, sitting on the Desktop
- iPhone footage imported into Photos, often 4K HEVC or ProRes
- iMovie and Final Cut Pro libraries, which hold the original media plus generated render and optimized files
- Exported photo batches from Lightroom or Photos saved as full-size PNG or TIFF
These are also the files people do not want to delete. They want the recording of the client call, the family video, the finished edit.
That is where compression helps more than cleanup. A 4K screen recording re-encoded to 1080p H.265 is typically a small fraction of the original, and for something you will watch on a laptop the difference is hard to see. Reduce screen recording file size covers the capture settings, and HEVC vs H.264 explains why the codec matters. For phone footage, see compressing iPhone videos.
Which Mac Disk Space Analyzer Should You Use?
- You just want to know what is full, once: System Settings → Storage, then OmniDiskSweeper if you need folder detail. Both free.
- You want a visual map and do not want to pay: GrandPerspective. Color by file type.
- You check your disk regularly or System Data is huge: DaisyDisk, bought direct so you get purgeable-space purging.
- You are comfortable in Terminal:
du -h -d 1 | sort -hand skip the apps. - You manage several Macs: DaisyDisk's direct license covers 5 personal Macs for one price.
Whatever you pick, use the analyzer to find and Finder to delete. It is easier to recover from a mistake you made deliberately.
Keep the Big Files, Make Them Smaller
Once your analyzer has pointed at the Movies folder or a Desktop full of recordings, the next decision is delete or keep. Compression is the third option.
Compresto compresses video, images, GIFs and PDFs in batch on your Mac. Drop in a folder of screen recordings, iPhone exports, or image exports, pick a quality level, and it re-encodes them with hardware acceleration, locally, without uploading anything. You keep every file and get most of the space back.
Frequently Asked Questions
What is the best disk space analyzer for Mac?
DaisyDisk at $9.99 one-time is the best overall, thanks to its sunburst map and hidden-space breakdown. GrandPerspective is the best free visual option, and OmniDiskSweeper is the best free sorted list.
Does macOS have a built-in disk space analyzer?
Partly. System Settings → General → Storage shows categories, large files, and iOS backups, but no folder map, and System Data has no breakdown. Finder's Calculate all sizes and du in Terminal fill the gap.
Is DaisyDisk worth paying for?
If you check your disk more than once, yes. $9.99 covers up to 5 personal Macs and explains hidden and purgeable space. For a single scan, the free tools find the same large folders.
Is GrandPerspective free?
Yes, from SourceForge. The $2.99 Mac App Store version is the same app and supports development. The latest release needs macOS 14 or later.
Is OmniDiskSweeper still maintained?
Yes. Version 1.16 is free from The Omni Group and runs natively on Apple silicon. It shows a sorted list, not a chart.
Why does my disk analyzer show less used space than macOS?
The analyzer cannot read everything: protected folders, local Time Machine snapshots, and other volumes. Grant Full Disk Access and rescan. A few gigabytes of difference is normal.
What usually takes up the most space on a Mac?
Video, in most cases: screen recordings, iPhone footage, and iMovie or Final Cut Pro libraries. Then old iPhone backups, Time Machine snapshots, and caches.
Is Disk Inventory X still a good choice?
No. Its last version lists macOS 10.13 to 10.15 support. GrandPerspective offers the same treemap view and is actively maintained.