iMac and MacBook come with lots of space so that the user can download and store many things. However, storing applications like the iPhoto Library, iMovies, or iTunes can take up close to 128 GB of disk space. Over time, the startup disk (Macintosh HD) becomes crowded, at which point the user receives this error notification:

your startup disk is almost full

The notification means that you can keep loading things onto your hard drive for a little while, but soon there won’t be any space left. After you check the box not to be warned again, the next notification will be that you are full and that somethings need to go. You should maintain a minimum of 15% free space on your startup disk to keep your Mac healthy.

Find the Big Files

Your startup disk contains partition of a drive or volume that houses the operating system for Mac. Typically, Mac has only one startup disk while some use two or three. Your hard drive should hold about 500GB. Find out what files are taking up the most space on your Mac. In Finder, go to Preferences and check ‘Hard disks’. The desktop will display all hard disks on the computer. Only one disk should show up in the window.

restart in Target Disk Mode

The computer startup disk is named in the window with the option to restart in Target Disk Mode. The Mode allows you to transfer your files in and out of two internal drives quickly without booting up. This is a good option to move very large media files, such as videos or movies, disk images, or libraries.

To manually search for the biggest files on your startup disk, in Finder, press Command + F shortcut keys. Go to Kind > Other > File Size on the attribute list. Click the second filter and select “is greater than”. Then enter the size parameter in the third space (like > 10 MB) and select ‘This Mac’. The list of files and apps will list the files larger than 10 MB on the hard drive.

As you will see, the largest files in the window are application files. You can uninstall applications that you don’t need or haven’t been using lately.

Deleting files is the only way you are going to solve the disk almost full problem outside of using an external hard drive for the extra space. Once you discover the largest files, especially the ones that haven’t been used in a long time, you can decide which ones can be deleted without harming your configurations. The .ipas from backups, zip archives, duplicate files, message attachments, and large application files as such can probably be deleted without any trouble. In this window, you can delete the files by dragging them to the trash. The large files can be also converted into a Smart folder by selecting the ‘Save’ button.

You can also view the system Storage Summary. Go to Apple > About This Mac > Storage. In the Storage usage, you can see the disk space consumers and what types of files they are. You can also click on ‘Manage’, which will open the menu to show what Optimized Storage can do to solve the problem on macOS Sierra or higher. Optimized Storage will move your junk files to iCloud Storage (until eventually, you will have to pay for the storage).

Note: typically, the Downloads folder will contain some of the largest files on your hard disk. An investigation of the large files in your Downloads folder will reduce the used space on your Mac by a wide margin.

In severe cases, you can also use MacCleaner Pro to help regain control of your startup disk space for about $25:

MacCleaner Pro divides the files into Junk, Applications, duplicates, and Large & Old and it even measures the hidden files. In top left corner, it tells how many GBs can be removed. The largest consumers are the large, old files that are not even in use.

1. Clean Your Cache

Many of your cache files help your Mac to run programs. However, the size of the cache can become very large. You can delete the files in your cache and your computer will create new ones. To clean your cache, go to Finder. Click ‘Go To Folder’ and type in ~/Library/Caches. Delete the files. Go to ‘Go to Folder’ and type /Library/Caches and delete the large folders. Be careful trying to remove the /System/Library/Caches folder as you may need some of those items.

2. Delete Localization files

You can also delete your localization files or language packs. In Finder, go to Applications. Use Control + click shortcut key on the application. Choose ‘Show Package Contents’. Go to Contents > Resources and search for .lproj files. Throw the language files you will not use in the trash.

3. Delete iOS Backup Files in iTunes

To delete those iOS backup files in iTunes, Launch iTunes and go to iTunes Preferences. Select ‘Devices’. In the backup list, choose the backup files you want to delete.Select ‘Delete Backup’. You can also choose to prevent iPads, iPods, and iPhones from syncing with your Mac by checking the box. Exit out of iTunes. You can restart your Mac (optional). Note: These backup files cannot be recovered once they are deleted.

4. Clear Up Some Space by Exporting to an External Drive

Some of your files you do need, and deleting them would be chaos. To keep those files and still reduce the amount of used space on the startup disk, you can export some of those files to an external drive. However, even if you use an external drive to have more space, if you do not delete some files from your internal disk, the computer performance will still be effected. Your startup disk should not remain almost full while you fill up more space somewhere else.

Connect your external hard drive to your Mac with USB. In Finder, select the files or folders you want to transfer. Press Command to select all of the items. Press Command – N to open a second window and select your external hard drive from the list of devices. You may drag and drop the selected files and folders to the external hard drive. Wait a moment or two for the transfers to complete. When the transfers are complete, Press ‘Eject’ to disconnect the external hard drive.

4. Empty the Trash to Delete the Files

Once you delete your files, they remain in the Trash bin, which is just another folder until to empty it. Once you’ve deleted much of your old, unused large files, make sure you empty the Trash.

5. Restart Your Mac and Recheck Storage

After emptying your trash, restart your Mac. When it reboots, it helps to clear out virtual memory and temporary files that were previously being counted in your disk space along with private/var/cache folders items. Go to Apple > About This Mac and check your used storage again to see if you made any real difference and if it was enough to cancel your error message.

If you have not made a significant difference in the amount of used disk space, go back and repeat these steps.

6. Check Apple Support

A solution for using Snapchat on your Mac has been presented using Bluestacks and Google Play. Several solutions were also presented for common problems reported by the user installing Snapchat on Mac. If none of these solution solved your problem, contact Apple Support for assistance with your Accessibility features.