Tidy and find

How to clear storage on a Mac

Updated 25 October 2026 · 5 min read

How to use Storage settings to free space on a Mac, what System Data is, which deletions are safe, and the parts Orrel helps with and the parts it does not.

When a Mac warns that its disk is almost full, the fix is usually a few large things rather than thousands of small ones: old downloads, videos, phone backups, message attachments and files kept in two places. macOS shows you where the space has gone; the work is deciding what to let go.

Start with Storage settings

Choose Apple menu › System Settings, click General in the sidebar, then Storage. The coloured bar shows how the disk is used, and below it is a short list of recommendations. Depending on your Mac and version, you may see:

• Store in iCloud. Keeps Desktop, Documents and photos in iCloud and only recent or opened files on the Mac. Needs enough iCloud storage, which is a paid plan for most people.
• Optimise Storage. Removes films and TV programmes you have already watched in the TV app.
• Empty Trash Automatically. Deletes items that have been in the Trash for 30 days.

Below the recommendations, each category has its size. Click the info button (ⓘ) next to one to see and remove what is inside. The useful ones:

• Documents. Tabs for Large Files, Downloads, Unsupported Apps, Containers and a File Browser sorted by size.
• Applications. Apps by size, with when each was last used.
• Messages. Photos, videos and attachments kept from conversations.
• iOS Files. Appears if you have backed up an iPhone or iPad to this Mac. Old backups can be large.
• Trash. Files you have deleted still use space until the Trash is emptied.

Items removed from these lists are deleted, not moved to the Trash, so select carefully.

The usual large items

• Downloads. Installers, archives and videos that were needed once. See how to delete downloads.
• Videos and screen recordings. Compressing a keeper often saves a good deal. See how to compress a video.
• iPhone and iPad backups. Connect the device, select it in Finder's sidebar, click Manage Backups and delete the ones you no longer need. If you back up to iCloud, local backups may be redundant.
• Message attachments. In Messages › Settings › General, set Keep messages to 1 Year or 30 Days. Older messages and their attachments are deleted, so only do it if you do not need them.
• Photos. In Photos › Settings › iCloud, choose Optimise Mac Storage to keep smaller versions on the Mac and originals in iCloud.
• Duplicates. The same file downloaded or copied twice. See how to find duplicate files.

To find large files anywhere in your home folder, Storage's Large Files tab is quickest. Our guide to finding large files covers Finder searches and Terminal too.

System Data

System Data is what is left over after the named categories: caches, logs, local Time Machine snapshots, virtual memory and files apps keep for themselves. It is the category people most want to shrink and the one with the fewest safe controls. What helps:

• Restart. Temporary files and virtual memory are cleared.
• Let snapshots expire. If you use Time Machine, macOS keeps local snapshots and removes them as space is needed or once a backup completes. tmutil listlocalsnapshots / in Terminal lists them.
• Remove developer data. If you use Xcode, old simulators and build data can be large; remove them from Xcode rather than by deleting folders.

Deleting files from ~/Library or system folders by hand can break apps or lose data, and the space often returns as soon as the app runs again.

Empty the Trash

Every method above that uses the Trash frees nothing until you empty it. Control-click the Trash in the Dock and choose Empty Trash. This cannot be undone.

How Orrel does it

Orrel helps with the part that is your own files. Its Clean Up screen suggests things you may no longer need, each to review before it goes to the Trash:

• Old installers more than 30 days old.
• Forgotten downloads that arrived more than 90 days ago.
• Old screenshots more than 30 days old.
• Big old videos over 100 MB and unchanged for 90 days.
• Large files over 100 MB, whatever their age.
• Identical copies, matched by a SHA-256 hash of their contents, so only true duplicates appear.

For files you want to keep but smaller, Orrel compresses PDFs at three levels and only saves a result that is at least 5% smaller, and compresses videos and images. Each writes a new file beside the original so you can compare before deleting either. In search, a phrase such as videos over 1 gb lists the largest files directly.

Where Orrel stops

Orrel does not clean caches, logs, System Data, Time Machine snapshots, iPhone backups, Mail or Messages attachments, or the support files apps leave behind when you delete them. It never empties the Trash or deletes anything outright. Clean Up looks at your home folder as Orrel's library sees it, without ~/Library, hidden folders or external drives, and the duplicate scan skips files stored only in iCloud. For the system side of the disk, Storage settings remain the right tool.