For Mac users, QuickTime Player is the quickest and easiest way to trim media.
Step 1: When you open a video or audio file, Mac’s default viewing software is usually QuickTime Player. However, you can also left click on your media, hover over “Open with…”, and select QuickTime Player.
Step 2: After opening your file, if you hover over the “Edit” tab in the top menu, you will be able to see an option labeled “Trim…”, which can also be enabled with the keyboard shortcut “Command (⌘) T”.
Step 3: Drag the yellow bars on the start, and end, side of your media to isolate your desired section. Once you have selected the part of the media you want to save, press “Trim”.
Step 4: Once you’ve trimmed your media, the cropped video will be displayed to you, titled “Untitled”. Make sure you name and save your new media, “Command (⌘) S” or “File” and “Save”. Your original, full-length, media is still saved under the original name of the file.