How to Change the Aspect Ratio for YouTube Shorts

Got a fantastic landscape video that looks awkwardly cropped or surrounded by ugly black bars on YouTube Shorts? You’re not alone. The secret to getting that polished, full-screen look is all about matching the right aspect ratio. This guide will walk you through exactly how to change your video's aspect ratio for YouTube Shorts, making sure your content looks professional and engaging every single time.

Why Aspect Ratio is a Big Deal for YouTube Shorts

Before we get into the "how," let's quickly cover the "why." Aspect ratio is simply the proportional relationship between the width and height of a video. For traditional YouTube videos you watch on a computer, the standard is 16:9 - think of your widescreen TV. But YouTube Shorts, like TikTok and Instagram Reels, live in a vertical world built for mobile phones.

The ideal, non-negotiable aspect ratio for YouTube Shorts is 9:16. This is portrait orientation, perfectly filling a smartphone screen when held upright. The best resolution to aim for is 1080 pixels wide by 1920 pixels tall (1080x1920).

What Happens When You Upload the Wrong Format?

If you upload a standard 16:9 horizontal video directly to Shorts, YouTube has to make a choice, and neither option is great for you:

• Automatic Cropping: YouTube might try to guess where the main action is using a pan-and-scan effect, aggressively cropping the sides of your video to make it fit vertically. You risk losing key visual information and ruining your intended framing.
• Letterboxing: To show your entire horizontal frame, YouTube will place it in the middle of a vertical frame and fill the empty space above and below with black bars. This makes your video look smaller, feels less immersive, and screams "amateur content" to viewers scrolling through a feed of full-screen vertical content.

Both outcomes lower the viewer experience, which can tank your watch time and engagement. The YouTube algorithm is smart, it favors content that provides a seamless, native experience on the platform. Making your video fit the 9:16 format is step one to giving your Shorts the best possible chance to succeed.

How to Change Video Aspect Ratio: Step-by-Step Guides

Now for the good part. Converting your videos is easier than you think, and you don’t need expensive or complicated software. Here are a few methods using popular and often free tools on both mobile and desktop.

1. On Your Phone: Using CapCut (Free & Powerful)

CapCut is a free video editor that has become a creator-favorite for a reason. It’s incredibly intuitive and packed with features perfect for short-form video. It is hands down one of the best tools for this job.

Step-by-Step Instructions:

1. Start a New Project: Open CapCut and tap "New project." Select the video from your camera roll that you want to convert and tap "Add."
2. Change the Aspect Ratio: Once your video is loaded into the timeline, look at the bottom toolbar. Find and tap the "Ratio" or "Format" icon. A list of presets will appear. Select 9:16. You'll immediately see the project canvas change to a vertical format, with your horizontal video sitting in the middle.
3. Reframe Your Video Clip: Now you have to decide how to fill the vertical space. Tap on your video clip in the timeline (it will get a white border). Now you have a couple of solid options:
   • Option A: Zoom and Pan (The Cropping Method): Place two fingers on the video in the preview window and pinch outwards to zoom in. The goal is to make the video fill the entire 9:16 canvas. Once zoomed, you can drag the video left or right to keep the most important person or object centered in the frame. This method crops the sides of your original footage, so it works best when your subject is already somewhat centered.
   • Option B: Use a Blurred Background (The No-Crop Method): If you don't want to crop your video, you can place it over a blurred background. In the bottom toolbar, go back to the main menu and select "Canvas." Then tap "Background" and choose "Blur." CapCut will automatically use a blurred version of your own video to fill the background. You can adjust the level of blur to your liking. This creates a professional look without sacrificing any of your original video's width.
4. Export: Once you're happy with the framing, tap the export icon in the top right corner. Make sure the resolution is set to 1080p and the frame rate is set to 30 for the best quality on Shorts. Tap "Export" and your new vertical video is ready to upload!

2. Using Canva's Video Editor (Great for Branding)

Canva isn't just for graphics, it has a surprisingly capable video editor that’s an excellent choice if you also want to add branded text, logos, or other graphic elements to your Short.

Step-by-Step Instructions:

1. Start with the Right Template: Open Canva on your desktop or mobile app. In the search bar, type "YouTube Shorts" or "Mobile Video." Canva has pre-made templates with the correct 9:16 dimensions (1080x1920 pixels). Choose a blank template to start from scratch.
2. Upload Your Video: In the left-hand menu, go to the "Uploads" tab and upload your horizontal video file from your computer or phone.
3. Add and Position Your Video: Once uploaded, drag your video from the panel onto the blank vertical canvas. By default, it will be placed in the center. Now, you can resize it.
4. Choose Your Framing Style:
   • Fill the Frame: Drag the corners of your video clip outwards until it completely covers the 9:16 canvas. Then, you can double-click the video to enter "crop mode," allowing you to slide it left or right to position the focal point perfectly in the center.
   • Styled Background: Alternatively, you can keep the video smaller and use Canva's tools to create a branded background. Select the canvas itself, and you can change the background color, add a pre-designed animated background from Canva's library, or even a static brand pattern. Then, you can easily drag text boxes over the video to add titles or captions.
5. Download Your Video: When your design is complete, click the "Share" button in the top right, then select "Download." Make sure the File type is set to "MP4 Video" and download your finished Short.

3. On Desktop (Online): Using an Online Editor like Kapwing

If you prefer working on a desktop but don't want to download any software, a browser-based tool like Kapwing is a fantastic choice. It’s powerful, fast, and has a generous free tier.

Step-by-Step Instructions:

1. Upload Your Media: Go to Kapwing's website and either drag-and-drop your video file or click to upload it.
2. Set the Canvas Size: As soon as your video is uploaded, look at the editing panel on the right side. Under "Canvas," you'll see options for "Output Size." Choose the 9:16 preset. The canvas will immediately snap to the correct vertical dimensions for YouTube Shorts.
3. Reframe Your Content: Just like with the other editors, click on your video clip. You can now resize it and drag it to the desired position.
   • To fill the screen, drag the corners until no background is visible. Use the "Lock Ratio" option to avoid distorting the video as you resize it.
   • If you want the blurred effect, you can duplicate your video layer, place the bottom one as the background, expand it to fill the canvas, and apply a blur effect from the "Adjust" panel.
4. Export and Download: Click the "Export Project" button at the top. You can choose your output settings (MP4 is best), and once it's done processing, you can download your resized video without a watermark (on the free plan).

Tips for Making Your Horizontal Video Shine as a Short

Simply changing the aspect ratio is only half the battle. Good repurposing requires a bit of creative thinking to make sure the vertical format works for your specific video content.

Focus on the Main Character

If your main subject moves around in the horizontal frame (for example, a person walking from left to right), you can’t just zoom in and hope for the best. In tools like CapCut or Kapwing, you may need to use keyframes or simply split the clip into multiple parts. In the first part, you frame the subject on the left of the screen. When they move across the center, you make a split and then reposition the second part of the clip so they remain in the frame. It takes an extra minute but makes the video feel like it was *meant* to be vertical.

Watch Out for the UI Overlays

Remember that the YouTube Shorts interface covers parts of the screen. The bottom of the video is where the channel name, caption, and engagement buttons (like, comment, share) are displayed. Avoid placing important text, captions, or crucial visual elements in the bottom 15-20% of the screen, as they will likely be blocked. Keep your critical information a little higher up.

Quality In, Quality Out

When you zoom in and crop a horizontal video, you're essentially blowing up a portion of the original footage. If your original video was shot in 720p or lower, zooming in may result in a blurry or pixelated final product. For the best repurposing results, always start with high-quality source footage (1080p at a minimum, 4K is even better).

Final Thoughts

Changing your video's aspect ratio to 9:16 is a fundamental step for succeeding with YouTube Shorts. Whether using a mobile app like CapCut, a design tool like Canva, or an online editor, you can quickly reformat horizontal content into an engaging, full-screen vertical video that looks natural in the Shorts feed.

Once you've got your perfectly formatted Shorts, streamlining your content calendar is the next step. Here at Postbase, we are obsessed with making social media management simpler, especially for video-first platforms. We built our platform to handle short-form video formats like YouTube Shorts, Reels, and TikToks flawlessly. With Postbase, you can plan all of your content on one visual calendar, schedule it across every platform at once, and trust that it will publish reliably - something legacy tools often struggle with.