How to compress large photos and videos to save space on a Mac

In the Disk tool, the Compress section finds photos over 2 MB and videos over 50 MB in your Downloads, Desktop, Documents, Pictures and Movies folders, recompresses the ones you pick, and moves each original to the Trash. It saves space, but the result is lossy, so do not use it on files where the best quality matters.

Steps

1. Open the notch, choose Disk, then the Compress section.
2. Press Find large media. NotchStar lists the large photos and videos it can shrink, biggest first. The scan covers JPEG, HEIC, MOV, MP4 and M4V files.
3. Every file starts selected. Click a row to leave it out, such as originals for printing or editing.
4. Press the button at the bottom right, labelled with the number of files and their total size, for example “Compress 3 (1.2 GB)”. Progress reads “Compressing 2 of 6” with the space saved so far. Press Stop after this one to cancel the rest.
5. Open the compressed files and check them. Look at a video to the end, and zoom into a photo.
6. If you are happy, empty the Trash when you choose. If not, put the original back from the Trash.

What changes

Photos are encoded again at a lower quality setting in the same format, and NotchStar keeps the photo’s metadata such as location and orientation. Videos are encoded again as HEVC, which many apps and devices read, though not all older ones do. The new file takes the place of the old one at the same path, and the original goes to the Trash. A result is kept only if it is under 90 percent of the original size. Otherwise it is thrown away and the original stays where it was. The Activity section charts the space you have recovered over the last 14 days.

When not to use it

• Camera originals and masters. Keep full quality copies of anything you will edit or print.
• Files someone else needs in a specific format. Check the format with them first.
• Work in progress. Do not compress a file that another app has open.

Limits

• Lossy. There is no way to restore detail afterwards except from the original in the Trash. Once you empty the Trash, it is gone.
• Five folders only. The scan covers Downloads, Desktop, Documents, Pictures and Movies inside your home folder.
• No format choices or quality slider. NotchStar picks the settings.
• Scans start only when you press the button. Nothing runs in the background.
• Large videos take time. Do not quit the app partway.
• It cannot tell which files matter to you. Only you can.

To see where the space is going before you compress, use Space and Duplicates, described in finding large folders and duplicates. The Disk page lists every section and safety rule.