Filmora
Filmora - AI Video Editor
Edit Faster, Smarter and Easier!
OPEN
Auto Reframe with Filmora
  • Automatically resize videos to ensure the focus.
  • Convert horizontal video to vertical and vice versa.
  • Support multiple aspect ratio.

How to Resize Video on Desktop/Mobile/Online

James Hogan
James Hogan Originally published Sep 19, 24, updated Oct 28, 24

When you shoot a video, it might not always be in the ideal size or aspect ratio for where you plan to upload or display it. The aspect ratio refers to the width and height ratio of your video. And if you get it wrong, it might not look right on your device or platform.

For example, if you upload a video with a 4:3 ratio to a widescreen platform, some parts of the video could be cropped out or the images might be distorted and stretched out. When it happens, what you need to do is resize your video.

There are many ways to resize your video, depending on your devices. You can do it on your computer, which offers greater control and high-quality results, do it on mobile, or use an online video resizer.

resize video guidance
In this article
    1. Common video sizes and resolution for guidance
    1. Solution 1: Auto Reframe
    2. Solution 2: Change Project Aspect Ratio
    3. Solution 3: Use the Crop Tool
    1. How to resize video online using Resize Video

Part 1. Common Video Sizes and Resolution

When you want to resize a video, you'll usually be presented with pixel sizes, aspect ratios, and resolution. They are different yet interconnected factors that significantly influence the quality of your video.

1. Pixel Size

Pixel size refers to the number of pixels that make up the dimensions of your video. The larger the pixel size, the more detailed the video can be. For example, a video with a resolution of 1920x1080 has 1920 pixels in width and 1080 pixels in height.

2. Aspect Ratio

The aspect ratio is the proportional relationship between the width and height of your video. It's expressed as a ratio that affects how the video is displayed on different screens. Some common video sizes and aspect ratios:

  • 1:1 (Square): A balanced, symmetrical format often used for social media posts, particularly on platforms like Instagram
  • 9:16 (vertical): A mobile-friendly format perfect for vertical videos on platforms like TikTok, Instagram Stories, and Snapchat.
  • 16:9 (widescreen): The ideal format for YouTube, television broadcasts, and DSLR video recordings
  • 4:3 (Fullscreen): A traditional aspect ratio used in older television broadcasts
  • 21:9 (Cinematic Widescreen): A wider format that provides a cinematic feel, often used in movies and ultra-wide displays

3. Resolution

Resolution refers to the total number of pixels in a video, usually noted as the width x height (e.g., 1920x1080). Higher resolutions mean more pixels, which generally leads to better image quality, as they capture more details.

Common video sizes and resolution for guidance

Pixel size Aspect ratio Resolution
Standard Definition (SD) 640 x 480 4:3 640 x 480
High Definition (HD) 1280 x 720 16:9 1280 x 720
Full High Definition (FHD) 1920 x 1080 16:9 1920 x 1080
Ultra-High Definition (UHD) 3840 x 2160 16:9 3840 x 2160
4K UHD 4090 x 2160 1.9:1 4090 x 2160
filmora box
Filmora Video Editor

Wondershare Filmora - Auto Resize Video

• Auto reframe video in 16:9, 1:1, 9:16, 4:3 or 21:9
• Offers cool video effects and filters to make your video become professional
• Cross-platform supported - (Windows, Mac, iOS, Android)

Part 2. How to Resize Videos on Mac/Windows

Resizing videos on a desktop provides a level of control and precision that mobile apps or online tools often can't match. One of the best software for this purpose is Wondershare Filmora.

Filmora is known for being incredibly user-friendly yet it's packed with advanced features that help you achieve professional-quality results with ease. One of its powerful features is Auto Reframe. This tool simplifies the process of resizing your video for different aspect ratios. It automatically tracks and detects the most important part of your video and adjusts the framing accordingly.

auto reframe filmora feature

Filmora is available for download on Windows and Mac, so make sure to install or update it to the latest version before continuing. The steps for resizing videos in Filmora on both platforms are quite similar, with three main methods to achieve this.

Get Started for Free
Get Started for Free

Solution 1: Auto Reframe

Step 1: Open the Auto Reframe feature and import your video

Open Filmora, and locate the Auto Reframe option in the AI Toolbox on the right side of the interface. Click on it to access the reframing feature. After that, a new window will appear, which lets you import your video file.

access auto reframe filmora

Alternatively, you can also access the Auto Reframe feature from the editing interface. First, create a new project and import your media. Once imported, go to Tools > Auto Reframe or right-click the video in the media library and choose Auto Reframe.

open auto reframe from interface

Step 2: Adjust the Aspect Ratio

On the Auto Reframe window, there are multiple aspect ratio templates available, including square (1:1), vertical (9:16), standard (4:3), widescreen (16:9), and cinema (21:9). Select the one that fits your needs.

adjust aspect ratio

After setting your preferences, click on the Analysis button. Filmora will take a few moments to analyze your video.

Step 3: Preview and make further adjustments

Once the settings and reframing are complete, preview your video. If further adjustments are needed, you can pause and play the video to adjust the frame. Move the framing box to the desired position by dragging it with your mouse. Repeat this process throughout the video as necessary.

Get Started for Free
Get Started for Free

Solution 2: Change Project Aspect Ratio

If you want a more straightforward approach, you can change the project aspect ratio. After importing your video to Filmora, click the Settings button and select “Change Project Aspect Ratio.

open video settings on filmora

Then, you'll get to change the aspect ratio as well as the resolution and frame rate.

change aspect ratio project settings
Get Started for Free
Get Started for Free

Solution 3: Use the Crop Tool

Lastly, you can use the traditional Crop tool to resize your video. To do this, select the video in the timeline and click the Crop icon to access the Crop and Zoom panel. Alternatively, you can right-click on the clip in the timeline and choose the Crop and Zoom option.

open crop and zoom panel

In the Crop and Zoom panel, configure the crop area by selecting from the available ratio presets.

select the aspect ratio

Adjust the size and position of the crop area by dragging the corner handles of the rectangle. Once done, click "Apply" to save your settings.

adjust the frame
Get Started for Free
Get Started for Free

Part 3. How to Resize Video on iPhone and Android

For those who prefer mobility and make quick and simple adjustments, you can also resize videos using Filmora on mobile. Although it may not offer more comprehensive features available in its desktop counterpart, you can resize your video using the simple cropping tool.

Filmora for Mobile

Edit Videos on Your Mobile Phone with 1-Click!hot

  • • Powerful Brand New AI Features.
  • • User-friendly video editing for beginners.
  • • Full-featured video editing for professional.

4,085,556 people have downloaded it
logo trustpilot 5 stars 4.5/5 Excellent

Filmora is available for download on Google Play Store (for Android) and App Store (for iOS). The steps for resizing videos are similar across both platforms. Once you have it installed on your phone, you can follow the steps on how to resize videos on mobile below.

Step 1: Import your video

After launching the app, tap on "New Project" to start editing. Select the video you want to resize and tap "Import."

import video for resize

Step 2: Start cropping your video

To crop your video, start by tapping the "Trim" button. Then select the "Crop" option. At the bottom, you'll see five aspect ratio choices: Original, 1:1, 4:5, 16:9, and 9:16. Choose the ratio that best fits your needs and adjust the cropping area by moving the marquee.

select aspect ratio on mobile

You can opt for “Free” if you want to manually adjust the crop area. Click Done to save the changes.

icon note
Note: If you want to change the resolution, you can do so when exporting the video file.

Part 4. How to Resize Videos Online

Resizing videos online offers a convenient option for those who prefer not to install software or need a quick solution. However, keep in mind that some online tools have file size limits that may not work well for large videos.

Here, we will use Resize Video to show you how to resize your videos online for free. Resize Video allows you to adjust the resolution of your video or scale it as needed.

How to resize video online using Resize Video

Step 1: Visit Resize Video website and upload your video

Go to the Resize Video website and upload your video (max. 500MB).

resize video online for free

Step 2: Choose your resize option

Next, choose one of the following options: scale the width while maintaining the aspect ratio, resize and crop the video to fit a fixed screen size, or add black borders. Then, input the pixel width you'd prefer.

select the resize option

Click "Upload" to proceed. The process usually takes a few seconds to a few minutes, depending on the size of your video. Once completed, you can save the resized video to your device.

Conclusion

Resizing video is often necessary to ensure that your content appears as intended across different platforms and devices. This way, you can maintain the quality and avoid issues like distortion, so that your content fits the required specifications for each platform.

You can resize video using video editing software, mobile apps, or video resizer online. One of the best tools is Wondershare Filmora, known for its useful Auto Reframe feature. Since it's available across platforms, you can conveniently resize your videos whether you're working on a desktop or mobile device.

Get Started for Free
Get Started for Free
James Hogan
James Hogan Oct 28, 24
Share article: