Although iMovie on Mac may allow you to convert your video to square with an aspect ratio 1:1, it always display it in 16:9 dimension screen as a square with black bars around it to make it fit the screen. And when you export the square video, it will still be square with black bars.
Frankly speaking, iMovie itself doesn't have the capability to export your movie into a square natively. But you can crop the iMovie to square with another software, like Keynote (a presentation software that comes preinstalled on Mac OS). Or you can even rely on an online video maker to make a square video directly. So, here goes.
Part 1: How to Make iMovie Square Video - Crop iMovie to Square
As we said before, there's no way to create square videos without black bars using iMovie. But you can use iMovie to edit the video and then use Keynote to change the dimensions and crop the iMovie to square.
Part 2: How to Make a Square Video Online with FlexClip on Mac
There’s also a much easier way crop your iMovie to square or directly make square videos for social media, like Instagram and Facebook.
FlexClip video maker makes it a breeze for anyone to create square videos in a snap!No download is needed! No design experience is required!
With FlexClip, creating a square video is pretty easy - simply pick a aspect ratio you want to convert your iMovie to, in our case to a 1:1 square aspect ratio, upload your video, add text, overlays, elements, and more to create a beautiful square video!
Now Let's walk you through the exact steps you’d need to take to create a square video using FlexClip.
Image Board: Make a Square Video - Add Media
Image Board: Make a Square Video - Change Aspect Ratio
Image Board: Make a Square Video - More Edits
How easy it is! Now, you can share square videos on Instagram or Facebook or wherever you want to share them!