Step one: Identify space hogs and optimise storage
The bigger the file, the more you’ll gain by trashing it.
Your Mac’s built-in primary drive, called Macintosh HD by default, is where all your files are stored, unless you saved them to an external drive. Check both for anything you don’t need to keep.
1 Get an overview
The status bar at the foot of any Finder window (show or hide it with Cmd-/) lists free space on the current drive. For more detail, choose About This Mac from the Apple menu and click the Storage tab. Wait for the chart to update fully and you have a color-coded breakdown of all drives. This doesn’t reflect how files are arranged on the disk, just how much space they use. If it shows that photos and/or music are the major space hogs, we’ll cover that in a few pages.
2 Manage documents
Click Manage to open the Storage Management window. You’ll see that the first of the panes listed on the left is Recommendations. As well as options to keep more content only in iCloud, which we’ll look at over the page, this lets you set the Trash to auto-empty and offers a Review Files option to “reduce clutter”. This opens the Documents pane, which deals with files stored anywhere in your Home folder.
Large Files lists only the biggest. Simply click a file to show its location; click Delete to erase it. File Browser shows which folders contain the most data. However, if you keep work outside your Home folder, none of this may help much.
The status bar at the foot of any Finder window lists free space on the current drive.
3 Delete downloads
The Documents pane also has a tab for your Downloads folder, which often contains disposable files such as installers. You can also open Downloads from its icon in the Dock, or from your Home folder in the Finder.
Click the Size column heading (Opt-click any heading and check Size to add it) to order by file size, clicking again if necessary to get the biggest first. Starting from the top of the list, delete anything you don’t need.