- Changing the aspect ratio of a video in CapCut on a computer
- Changing a video's shape with the CapCut online resizer
- Changing aspect ratio in the CapCut phone app
- What fills the gaps after changing a CapCut video's shape
- Using Auto Reframe so your subject stays in the CapCut frame
- Picking the right CapCut aspect ratio for your business videos
- If the CapCut ratio change leaves your video stretched or cropped
- Frequently asked questions
To change the aspect ratio in CapCut on desktop, import your video, click the ratio control and pick a shape such as 9:16, 16:9 or 1:1, then export. The detail people trip over: a new shape leaves empty space, which CapCut says you can fill with a colour, blur or image.
You filmed a lovely wide clip, and now it has to go on TikTok, where it shows up as a thin strip with black bars above and below. Or you've shot a vertical video and your website needs it wide. The fix is the aspect ratio, which is just the shape of the frame, and CapCut lets you change it in a few clicks.
The tricky bit is that the control has a different name on each version of CapCut, and the shape you pick decides what happens to the empty space. I've gathered the steps from CapCut's own guides, with the presets it names and the ways it fills the gaps.
Changing the aspect ratio of a video in CapCut on a computer
On the desktop editor, CapCut's guide describes a ratio control that sits with your preview. The route looks like this:
- Open CapCut and click Import, then select the video from your computer.
- Click the ratio control and pick the shape that matches where you plan to share the video.
- Make any other edits you'd like, such as masks or feathering.
- Click Export and set the resolution, bit rate, codec, format and frame rate.
- Download the file, or share it straight from CapCut.
CapCut says it supports popular ratios like 1:1, 16:9 and 9:16, and more. The 9:16 shape is the tall one for phone screens, 16:9 is the wide one for YouTube and websites, and 1:1 is the square.
Changing a video's shape with the CapCut online resizer
If you'd rather work in a browser, CapCut's online version has its own route. Its resize guide goes like this:
- Launch the web version of CapCut and select New Video.
- Choose Upload and pick your MP4 file.
- Open the sidebar menu labelled Screen Aspect Ratio and select a format.
- Use the zoom and positioning tools to keep your main subject centred.
- Select Export and download the file.
CapCut's separate video resizer page works slightly differently: you choose the aspect ratio first, create the project, and then upload your video. It lists presets of 1:1, 2:1, 3:4, 4:3, 9:16 and 16:9, and says Instagram ratios also include 4:5.
Changing aspect ratio in the CapCut phone app
This is where the naming gets slippery. CapCut's own pages I could check cover the desktop and online routes in detail, but don't give one fixed button name for the phone app. On a phone, the ratio or format option normally sits in the toolbar along the bottom of the editing screen, and its label varies by app version.
So if you're on iPhone or Android, open your project, look along the bottom toolbar, and choose the option that mentions ratio, format or canvas. Tap one of the shapes, check the preview, and then export. If a step on your screen doesn't match, menus vary by app version.
What fills the gaps after changing a CapCut video's shape
Change a wide clip to 9:16 and you'll see empty bands above and below it. CapCut's guide lists how to fill them:
- Change the background colour.
- Blur the background, or blur specific elements.
- Add a background image.
- Add a video backdrop.
A blurred copy of your own footage behind the clip is the version most people choose, because it looks intentional rather than empty. A solid colour that matches your brand also works well for a business account.
Using Auto Reframe so your subject stays in the CapCut frame
When you squeeze a wide clip into a tall frame, the person or product can slide off to one side. CapCut describes Auto Reframe with AI as detecting the main focus of the video and adjusting the framing when you change the aspect ratio.
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CapCut's guide doesn't give a button name or steps for it, so if you can't spot it in your version, use the zoom and positioning tools from the online route to centre the subject by hand.
| Shape | What CapCut names it for |
|---|---|
| 9:16 | Tall phone video, such as Reels and TikTok |
| 16:9 | Wide video, such as YouTube |
| 1:1 | Square posts on a feed |
| 4:5 | Instagram Feed |
| 4:3 and 3:4 | Other presets listed in the resizer |
Picking the right CapCut aspect ratio for your business videos
The best shape depends on where people will see it first. For a small business or creator account, here's the rule of thumb I use:
- Starting on TikTok or Reels: go for 9:16 and keep key text away from the very top and bottom.
- Going on YouTube or your website: pick 16:9.
- Posting a clean feed grid: 1:1 or 4:5 suits it.
- Using one clip in several places: export a separate version per shape rather than stretching one.
If your clip is going out on TikTok, you might want captions in the right language too, so my guide to changing the language on TikTok is worth a look. And once a viewer lands on YouTube, they can adjust how fast it plays, which I explain in changing playback speed on YouTube.
If the CapCut ratio change leaves your video stretched or cropped
- Check you changed the ratio and not just zoomed. Zoom enlarges the picture and can cut off the edges.
- Use the positioning tools to move the subject back into view.
- Add a blurred or coloured background so the empty bands look planned.
- Export from the original file, not from a clip you've already resized once.
CapCut's own help pages are the best place to check your exact version if the menus look different.
Frequently asked questions
How do I change the aspect ratio in CapCut on a computer?
Import your video, click the ratio control, and pick a shape that matches where you'll share it, such as 9:16, 16:9 or 1:1. Then export.
What aspect ratios does CapCut offer?
CapCut says it supports popular ratios like 1:1, 16:9 and 9:16. Its online resizer lists 1:1, 2:1, 3:4, 4:3, 9:16 and 16:9, and says Instagram also uses 4:5.
How do I fill the empty space after I change the ratio in CapCut?
CapCut's guide lists a background colour, a blurred background, a background image or a video backdrop.
Can CapCut keep my subject in frame when I change the ratio?
CapCut describes Auto Reframe with AI as detecting the main focus of the video and adjusting the framing. If you can't find it, use the zoom and positioning tools by hand.
Where is the aspect ratio option in the CapCut phone app?
CapCut's pages I checked don't give a fixed button name for the phone app, so look along the bottom toolbar for a ratio, format or canvas option. Menus vary by app version.
