How to Change Aspect Ratio in iMovie on Mac

You can change the aspect ratio in iMovie by cropping your video in the media library before you add it to the project timeline. Go to the Cropping tool and adjust the cropping box to fit the area of the video you want to keep.

It’s important to note that iMovie does not have a feature to directly change the aspect ratio of your movie inside of the software. The exported movie will still be in a 16:9 aspect ratio.

Hi, I’m Nancy, and I have extensive experience working with iMovie. In this article, I will provide you with tips on how to creatively crop your videos and suggest alternative programs that you can use to change the aspect ratio on your videos.

What is the Default Aspect Ratio in iMovie?

The default aspect ratio in iMovie is 16:9, which is the standard widescreen format used for most video content. To capture a video in 16:9 on your device, such as a smartphone or camera, you should hold it in the horizontal orientation or landscape mode.

How to Change the Aspect Ratio to Portrait in iMovie?

The aspect ratio 9:16 is the most common format for videos on TikTok, YouTube Shorts, and Instagram Reels. Follow the steps below to convert your 16:9 video into a portrait or vertical orientation.

Step 1: Import your video clip into the Media Library. Click on the video clip and then select the Cropping tool. Adjust the cropping box to turn it into a vertical orientation and select the Apply button. 

Keep in mind that once you crop the video, only the content within that cropped area will be visible in the clip.

Step 2: After cropping your video clip, add it to the timeline in iMovie. You will notice that the clip is centered and has two black bars on either side. However, if you export the video without any further adjustments, it will still have a 16:9 aspect ratio and be in landscape mode.

Step 3: Now we need to get rid of the black bars on the sides. Once again, go to the Cropping tool and then rotate the video clip clockwise. Next, select the Crop to Fill option to fill in the frame. 

Step 4: Export the file in the highest resolution and quality and save it onto your computer.

Step 5: If you open your video file in Quicktime Player to view it, it will still be in landscape mode. 

To change the aspect ratio of your video to a vertical format of 9:16, you can go to the menu bar at the top of Quicktime Player, click on Edit, and select Rotate Left. Now your video will be in portrait mode.

After rotating the video, you can upload it onto any social media platform that supports the dimensions of 1080 x 1920 pixels. 

Why Can’t I Change the Aspect Ratio in iMovie?

iMovie automatically sets the aspect ratio of the project to 16:9 and there is no built-in feature to directly change the aspect ratio of your movie. If you want to use a different aspect ratio, you’ll need to manually crop the video to achieve the desired aspect ratio.

2 Free Alternatives to iMovie for Resizing Videos

There are many different aspect ratio sizes that are available to choose from. Here are two great alternative programs to try if you need to resize your video.


Canva is a free graphic design platform that offers a vast library of pre-made templates and tools for users to create any type of visual content. If you want to modify the aspect ratio of your video, you can create a new design with custom dimensions or choose from a diverse selection of video templates that are optimized for popular social media platforms. 

With Canva’s video editing tools, you can easily customize your videos and enhance them by adding audio, images, animated stickers, and other elements.


Kapwing is a free web-based video editor that’s available to Windows and Mac users. The platform has all the important features of a professional video editing software, including the ability to change the aspect ratio of your video. 

Just go to the Canvas settings and select the aspect ratio you want from the Output Size options. Make sure to carefully select which part of the video you want to keep within the frame before applying any changes.


Here are the frequently asked questions about how to change the aspect ratio in iMovie.

Why Does iMovie Crop My Video When I Change the Aspect Ratio?

iMovie crops your video when you change the aspect ratio because it needs to fit the original clip into the new aspect ratio. Stretching or compressing the video would result in distortion, so cropping is necessary to avoid this issue.

Can I Change the Aspect Ratio in the iMovie 10 App?

Unfortunately, changing the aspect ratio is not possible in the iMovie 10 app for iPhone and iPad. The default aspect ratio remains in 16:9.

Final Thoughts

iMovie has limited options for resizing a video, which can be frustrating for creators who want to repurpose their existing videos into short-form content with different aspect ratios. Cropping the video is one way to change the aspect ratio in iMovie, but it may result in cutting off some parts of the original footage. 

Fortunately, there are other video editing programs available that provide the ability to easily change the aspect ratio of your videos such as Canva and Kapwing.

We hope you found this article helpful. If you have any other tips on how to change the aspect ratio in iMovie, please share them with us in the comments below.

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