Change Video Aspect Ratio to 16:9/4:5/1:1/21:9/9:16 for Free without Quality Loss

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Change Video Aspect Ratio to 16:9/4:5/1:1/21:9/9:16 for Free without Quality Loss

Last Updated: 2025. 04. 28

Summary

This blog offers you a vivid explanation of what aspect ratio is and shows you detailed steps to change video aspect ratio. Follow us and you will find changing video aspect ratio can’t be easier.

Table of Contents

Part 1. What is Aspect Ratio

Part 2. Frequently Used Video Aspect Ratios

Part 3. How to Change Video Aspect Ratio

Change Video Aspect Ratio with iMovie Change Video Aspect Ratio on Mobile Change Video Aspect Ratio Online Change Video Aspect Ratio with Auto Reframe

What is Aspect Ratio

The video aspect ratio describes the proportional relationship between the width and the height. Let’s say a video is 16 inches wide and 9 inches high, the video aspect ratio (the width to the height) is 16:9.

Here is the most important thing to note. The aspect ratio doesn't represent the actual width and height. That's to say, 16:9 videos don't necessarily mean a pixel size of 16*9, that would be too small.

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Frequently Used Video Aspect Ratios

Different video aspect ratios fit different devices and occasions. Here are several frequently used video aspect ratios and where they have been put into use.

21:9

21:9 videos are especially designed for cinematic, super widescreen, and ultra widescreen. People, except for professional movie directors, rarely produce 21:9 videos. The pixel sizes of 21:9 videos are 2560*1080, 3440*1440, and 5120*2160.

16:9

16:9 videos are more common than 21:9 videos. Nearly 60% of videos you see every day are 16:9 videos. Instagram, YouTube, DVD videos are all in 16:9. There are lots definations for 16:9 videos, ranging from 480*320 to 7680*4320.

4:3

4:3, also called the "academic format", is for movies made before the 1950s. Now, this video aspect ratio is rarely to be used.

1:1

1:1 video is also called square video. This kind of video is usually in 720*720 or 480*480. They are usually seen in Instagram and YouTube.

9:16

9:16 video, the vertical video, are spreading across all mobile devices, especially after more and more accepting Instagram and TikTok.

Part 3. How to Change Video Aspect Ratio

Videos in a wrong aspect ratio may give audiences an overly stretched look. To fix problems led by wrong aspect ratio, here in this part, we are showing you 4 ways to change video aspect ratio easily. Please pick the easiest method and follow.

How to Use iMovie to Change Video Aspect Ratio via iMovie

iMovie is the most handy video editing tool for Apple users. However, it has been criticized for not supporting 9:16 videos. Even though this Apple built-in video editing software still doesn't have native vertical video support, there is a hidden workaround that can help you change video aspect ratio. Check it out!

Step 1

Go to File > New App Preview. This helps you create a new blank project.

Step 2

Drag in an image with the right aspect ratio. For instance, if you want to change the video aspect ratio to 9:16, you need to add an image in 9:16 to iMovie's timeline first.

Step 3

Bring in your video clip to iMovie. It will automatically be in the same aspect ratio as the first photo you uploaded. Use the Crop tool to decide which area you want to keep.

Note

Currently, this method only works on your Mac computer. You can't change video aspect ratio on your iPhone/iPad like this.

Change Video Aspect Ratio on Mobile

Whether you are on iPhone or Android devices, you can directly convert video aspect ratio right inside the Album app. Here we will take Android devices as an example to show you how. Please mind that the detailed steps may vary on iPhone, but the aspect ratio conversion option always exists.

Step 1

Launch the Gallery app, find the video you want to change its aspect ratio.

Step 2

Click on the Edit option, look for the Aspect Ratio or Crop option.

Step 3

Select the desired aspect ratio, adjust the video and save the edited video.

Change Video Aspect Ratio Online

FlexClip is extremely handy in terms of tweaking video aspect ratio. It offers browser-based convenience. You can render among 5 common video aspect ratios without installation.

What truly sets FlexClip apart is its editing capability. Changing video aspect ratios may leave you tedious black bars. FlexClip can fill in the black bars with background colors you like.

Now, click on the Create a Video button and follow us to get started. FlexClip also provides numerous elegant templates in different aspect ratios. Check them out!

Create a Video

View Templates

Step 1

Upload

Go to the Media section, click on the Local Files icon and choose a video you want to change its aspect ratio. Drag and drop will also do. Apply to the timeline.

Upload Video to FlexClip

Step 2

Choose the right aspect ratio

On the upper left corner, select the right aspect ratio. You can choose 16:9, 9:16, 1:1, 4:5, 21:9.

Change Video Aspect Ratio at FlexClip

Step 3

Edit the video

Drag the video so that no important messages are missing. If necessary, use the color picker tool to fill in the black bars caused by aspect ratio conversion, drag the elements to reshape the frame. You can also try other video editing tools like filters, flip, video background removal, etc.

Edit the Video

Step 4

Download & share

Continue editing or save your video to desktop. You can also share the video to YouTube or via short link.

Change Video Aspect Ratio with Auto Reframe

Auto Reframe tool tracks the key moving object in your video using advanced AI. When changing the video aspect ratio, it automatcailly centers or pans the frame so that nothing important is cropped out.

We recommend using CapCut due to its ease of use, as well as multi-platform support. However, Auto Frame is one of the premium features. You have to subscribe Capcut at $7.99 per month to access this tool.

Step 1

Download CapCut on your desktop, launch it and then create a new project by uploading a video track.

Step 2

Click on the video in the timeline, go to Video > Basic > Auto Reframe. Select the aspect ratio, adjust the video stability and camera movement speed, confirm the change by choosing Enable.

Step 3

Hit Export, select video quality, frame rate, codec, etc and save it to your device.

How to Do Auto Reframe with CapCut

The Bottom Line

That’s all for 4 ways to change video aspect ratio. If you find this post helpful, please do remember to share so that others can also benefit.