Mac storage full? Start with the files you recognize.

Open the Apple menu, choose System Settings, then General and Storage. Your Mac will show how much space is available and group what is using the rest into categories.

Apple's Storage settings are the best free place to begin. Open a category to review its files, or use Show in Finder when that option is available. On older versions of macOS, start from About This Mac and choose Storage.

Downloads is usually easier to judge than an unfamiliar system folder. Look for installers you have already used, duplicate downloads and large files you recognize.

Size alone does not make a file unnecessary. If you do not know what something is, keep it until you can check. Review one small group at a time so it is clear what changed.

System Data is a broad label. Apple says it can include logs, caches, virtual memory files, temporary files, fonts, app support files and plug-ins. It is not one folder that can be safely emptied.

macOS manages much of this category itself, and its size can change. Avoid deleting files from Library or system folders simply because they look large. Use Finder or the app that created a file when you need to understand it first.

Photos, videos and work documents often free the most space, but they are also the hardest to replace. Before removing them, check that your backup exists and that you can open something from it.

Moving files to an external drive can help, but confirm the copy before deleting the original. Keep important files in the Trash until you are certain you no longer need them.