Mac storage full? Find what is using it and free up space safely

To free up space on a Mac, do three things in order. First, see where the space went. Second, remove the biggest things you are sure about. Third, check the numbers again. Most of the work is the first step, because guessing is how people delete the wrong thing.

This guide is the starting point. Each step links to a longer article if you want more detail.

Step 1: see what is using the space

Open Apple menu > System Settings > General > Storage. The bar at the top shows how your startup disk is used. The labels are broad, so treat it as a first look, not an answer. What is taking up space on my Mac? goes through the next layer down.

To read it yourself, Terminal can show the biggest folders in your home folder. This command only reads sizes and changes nothing:

du -sh ~/* | sort -h

It can take a minute on a big disk. The last lines are your largest folders. Hidden folders (those starting with a dot) are not in this list.

To check the whole disk, run df -h /System/Volumes/Data. The Avail column is what is really left on the part of the disk that holds your files.

Step 2: remove what is safe

Start with things that are clearly yours and clearly not needed.

Safe, Risky, Never

• Safe: the Trash once you have looked inside it, installers you already used, files in Downloads you have checked, apps you no longer open.
• Risky: large files you do not recognise, old iPhone backups (you may need them to restore a phone), anything inside your Library folder.
• Never: system folders, your Photos library contents, and anything you cannot name. If you are unsure, leave it.

The Trash

Moving a file to the Trash does not free its space. The space comes back when you empty it. Read why moving files to the Trash does not free up space if the number refuses to change.

Downloads and old installers

Downloads is where forgotten files pile up. Sort it by size and date, and remove what you have already used. See how to clean up the Downloads folder and how to delete DMG files.

Large files

A few big files usually matter more than thousands of small ones. Find large files on a Mac shows how, with Finder and Terminal.

iPhone backups

Old device backups can be many gigabytes each. Read iPhone backups on your Mac before you remove one, because a backup you delete cannot be recovered.

Caches and leftovers

Caches are copies apps can rebuild. Most are safe to clear, but not all. See what is safe to delete in Library Caches and leftovers from deleted apps.

Duplicates

Matching file names do not prove two files are the same. Finding duplicate files explains how to compare them carefully.

Step 3: check again

Open Storage settings again, or run df -h /System/Volumes/Data. If the number did not move as much as you expected, there are usually three reasons:

• The Trash has not been emptied.
• Local snapshots or purgeable space are holding some of it. macOS counts that as available and releases it when needed.
• You removed files that were clones or hard links, which share data with another file, so little space was freed. Mac storage full but no files? covers these cases.

Common questions about specific situations

• Your Mac says the disk is almost full and you need space now: startup disk full.
• An update will not install: not enough space to update macOS.
• It fills up again every few weeks: Mac keeps running out of space.
• The Library folder is huge: why the Library folder is so big.
• Mail, Messages or Photos: Mail, Messages, Photos library.

Habits that keep space free

A one-off cleanup helps, but small habits help more. Empty the Trash when you have checked it. Look at Downloads once a month. Remove apps you no longer use. Every few months, run the folder command from step 1 and see whether anything has grown. None of this needs special software, and it keeps the disk from filling up again without warning.

Let a scan do the looking

DiskJoy is our product. It scans the folders you choose and reports allocated bytes, a lower bound that leaves out space shared between files, with a short explanation for each item. A scan only reads sizes and dates and changes nothing. DiskJoy is pre-alpha and cleanup is not available yet, so for now it helps you see; you remove things yourself. Download DiskJoy for Mac if you want a clear picture before you start.

A short routine

1. Look at Storage settings.
2. Find the biggest folders and files.
3. Remove what you are sure about, starting with the Trash and Downloads.
4. Leave system folders and your Photos library alone.
5. Check again, and give macOS a little time to release purgeable space.