How to Free Up Space on a Mac (and the Windows Equivalents)
How to free up space on a Mac using the built-in storage tools, the folders that quietly fill up, what System Data really is, and the matching steps on Windows.
- Published
- Journey
- 4 min
- Covered here
- 8 sections
- Route
- Tech
Covered here
- See what is filling the drive
- Use the built-in recommendations
- Folders that quietly grow
- Track down the largest files yourself
- What is "System Data" on a Mac?
- How to free up disk space on Windows
- Mac and Windows tools side by side
- Keep it from filling again
The fastest way to free up space on a Mac is to open System Settings, choose General, then Storage, and work through what it shows: accept the recommendations that suit you, remove apps you no longer open, delete outdated iPhone backups, and move large media files to an external drive or cloud storage. A few corners that rarely get attention, such as the Downloads folder and old message attachments, often hold more than people expect. Windows has a matching toolkit, covered further down.
See what is filling the drive
The Storage page shows a coloured bar split into categories such as Applications, Documents, Photos, Messages and System Data. Each category with an "i" button opens a list sorted by size, so you can delete directly from it. On macOS Monterey and earlier, the same view lives under the Apple menu, About This Mac, Storage, then Manage.
Use the built-in recommendations
| Recommendation | What it does | Worth knowing |
|---|---|---|
| Store in iCloud | Keeps Desktop, Documents and photos in iCloud and leaves lighter copies on the Mac | Needs enough iCloud space; files download again when opened |
| Optimise Storage | Removes films and TV episodes you have already watched in the TV app | Purchases can be downloaded again later |
| Empty Bin Automatically | Deletes items that have been in the Bin (Trash on US-English Macs) for 30 days | Anything you binned by mistake has a month to be rescued |
Folders that quietly grow
- Downloads. Installer files ending in .dmg or .pkg, zip archives and duplicate copies pile up here. Sort the folder by size in Finder. Once an app is installed, its installer can usually go.
- iPhone and iPad backups. Under "iOS Files" in Storage, local device backups are listed by date. Remove the outdated ones once a newer backup exists.
- Messages attachments. Photos, videos and voice notes from chats add up over years. The Messages category lists the largest; Messages settings also let you keep conversations for 30 days or a year instead of forever.
- Mail downloads. Attachments you opened from Mail are often saved again in a hidden downloads folder; the Mail entry in Storage lists them for review.
- Audio and video projects. Editing projects keep render files and several exports. If you have been converting MP3 recordings into MP4 videos for sharing, keep the final files and the original audio, and let the drafts go.
- Duplicate photos. Recent versions of Photos gather likely duplicates in a Duplicates album, where you can merge them.
Track down the largest files yourself
- Open a Finder window and press Command-F.
- Set the search scope to "This Mac".
- Change the first criterion to File Size (choose Other… if it is not listed), then set it to "is greater than" and a size such as 1 GB.
- Look through the results and move or delete what you recognise. Leave anything inside System or Library folders alone unless you are certain what it is.
What is "System Data" on a Mac?
System Data is a catch-all for caches, logs, local Time Machine snapshots, virtual memory files and other material macOS manages itself. It often shrinks after a restart, and local snapshots are removed automatically when space runs low. Utility apps that promise to slash System Data deserve caution: deleting the wrong cache or support files can cost more time than the space is worth.
How to free up disk space on Windows
- Storage Sense. Open Settings, System, Storage, and switch on Storage Sense to clear temporary files and empty the Recycle Bin on a schedule you choose.
- Cleanup recommendations. On the same page in Windows 11, this lists large or unused files, files already synced to cloud storage and apps you rarely open.
- Temporary files. Review the categories and tick what to remove. Look twice at the Downloads box: ticking it deletes the whole folder.
- Disk Cleanup. Search for it in the Start menu, pick the drive, then choose "Clean up system files" to include leftovers from past Windows updates.
- Installed apps. In Settings, Apps, Installed apps, sort by size and uninstall what you no longer use.
Mac and Windows tools side by side
| Job | Mac | Windows |
|---|---|---|
| Overview of usage | System Settings, General, Storage | Settings, System, Storage |
| Automatic clean-up | Empty Bin Automatically | Storage Sense |
| Offload to the cloud | Store in iCloud | Files On-Demand for synced folders |
| System leftovers | Restart; macOS manages snapshots | Disk Cleanup, "Clean up system files" |
| Find big files | Finder search by File Size | File Explorer search by size |
Keep it from filling again
- Set a monthly reminder to empty Downloads and the Bin or Recycle Bin.
- Keep large archives on an external drive, and keep a second copy somewhere else so a single failed disk cannot take them.
- Check free space before a major system update, which needs room to download and install.
If you are clearing space because the laptop is about to change hands, the next step is a full wipe; see how to factory reset a laptop for Windows, Mac and Chromebook.
Spotted a mistake?
A short note is enough.
