Kempt
In short
Open System Settings › General › Storage and start with the biggest category you control: Applications, Documents, Photos or Messages.Delete old installers and duplicates in Downloads, empty the Trash, and turn on Optimize Storage. System Data is managed by macOS: you can’t clear it by hand, and it shrinks as caches are rebuilt. Kempt’s Clean Up finds the safe file-level wins and sends them to the Trash, with Undo.
Without any app
See what fills the disk
Apple menu › System Settings › General › Storage. Wait for the bar to finish counting, then read the list: Applications, Documents, iCloud Drive, Photos, Messages, Trash, macOS and System Data.
Use the recommendations
Store in iCloud keeps recent files on the Mac and the rest in iCloud; Optimize Storage removes TV movies and shows you’ve watched; Empty Trash automatically erases what has been in the Trash for over 30 days.
Delete the largest items
Click the info button next to Documents or Applications to list files and apps by size, and delete what you don’t need. Leave app support folders to their apps.
Downloads and installers
Sort Downloads by Size. Disk images (.dmg), packages (.pkg) and archives (.zip) are usually done once the app is installed; a single installer can weigh hundreds of megabytes.
Empty the Trash
Finder › Empty Trash. Space comes back only once the Trash is empty. Items deleted from iCloud Drive are removed after 30 days whatever the setting.
| Category | What it is | What to do |
|---|---|---|
| Applications | Your apps | Delete the ones you no longer use |
| Documents | Your files, outside other categories | Delete large files, installers and duplicates |
| Photos, Messages, Mail | Libraries and attachments | Manage in each app; Messages can keep messages for 1 year |
| Trash | Deleted, not yet erased | Empty it |
| macOS | The system itself | Nothing: keep macOS up to date |
| System Data | Logs, caches, temporary and support files managed by macOS | Nothing by hand; Apple says macOS manages it |
Categories as named in macOS 26 Tahoe’s Storage settings (Apple support, checked 29 Oct 2026).
With Kempt
- 1
Clean Up, by group
Installers for apps you already have, unfinished downloads, exact duplicates, similar copies, screenshots older than a month, old installers and archives, and large files (over 500 MB). The first three are pre-ticked; similar copies never are.
- 2
Nothing is deleted
Items go to the Trash, and every cleanup can be undone from Activity, with the reason each file moved.
- 3
What Kempt doesn’t do
Kempt cleans your files, not the system: it doesn’t clear caches, System Data or app leftovers. For that, Apple’s Storage settings are the safe tool.
$27 once, 14 days freeRuns on every Apple silicon MacA question? Ask a person
Questions people ask
What is System Data on a Mac?
Files outside the other categories: logs, caches, virtual memory, temporary files, fonts and app support files. Apple says its contents are managed by macOS and vary with the Mac’s state.
Why is my Mac storage full when I have few files?
Often System Data, local snapshots, Photos or Messages attachments, or a full Trash. Check each category’s size in General › Storage.
Is it safe to delete .dmg files?
Yes, once the app is in Applications. Kempt lists these as “Installers for apps you already have”.
Do I need a cleaner app?
Not to free space safely: macOS removes caches and logs it no longer needs, and Storage settings handle the rest. A file app helps with duplicates and forgotten installers.
How do I free up space on a Mac for an update?
The update tells you how much space it needs. Empty the Trash, delete old installers in Downloads, and turn on Optimize Storage in General › Storage, then try again.
Why is my Mac storage full but I can’t find the files?
Look at System Data, Photos and Messages in General › Storage. Large hidden items are often Messages attachments, Photos libraries or System Data, which macOS manages itself.
How do I clean up temp files on a Mac?
macOS removes temporary files and caches it no longer needs. Apple notes that starting up in safe mode clears some system caches, which frees space only for a while.