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Resize Video Online Free – Change Video Resolution to Any Size

Change your video to 4K, 1080p, 720p, 480p, or any custom pixel size directly in your browser. Pick a fit mode to control how the image fills the new frame. No uploads, no software, no cost.

Resize Video Dimensions

What Resizing Actually Does

Resizing changes the pixel dimensions of your video. Downscaling (4K to 1080p) shrinks the image and usually improves perceived quality. Upscaling (480p to 1080p) makes it larger but doesn't add real detail — it just spreads existing pixels across a bigger canvas.

The tool recalculates every frame to match your target dimensions. If aspect ratios don't match, the fit mode determines what happens: contain adds black bars, cover crops the edges, or fill stretches the image (which distorts it).

This runs entirely in your browser. No upload means faster processing and complete privacy. Processing time depends on video length and your computer's speed.

When You Need This

Meeting platform upload limits

Some platforms cap uploads at 720p or 1080p. If you shot in 4K, downscaling ensures your file gets accepted. Smaller resolution also means faster upload and smaller file size.

Matching clips from different cameras

One camera shot 4K, another shot 1080p. Editing them together causes issues. Resize everything to 1080p before importing to your editor for a smooth timeline.

Landscape to vertical for Reels or TikTok

Set width to 1080 and height to 1920, then use Cover mode. The tool crops the sides to fill the vertical frame. You lose the edges but get a full-screen mobile video.

Reducing file size for email

Email attachments usually cap at 10-25MB. Resizing 1080p to 480p cuts the pixel count by 75%, often enough to fit under the limit. Quality drops but it's shareable.

Custom banner or display sizes

Digital signage or web banners need specific dimensions. Turn off aspect ratio lock and type exact values. Use Fill mode to stretch the video to fit — just know it will distort.

Common Video Resolutions

NameResolutionUse Case
4K (UHD)3840 x 2160High-end production, future-proofing
1080p (Full HD)1920 x 1080Standard web video, YouTube
720p (HD)1280 x 720Faster uploads, smaller screens
480p (SD)854 x 480Email attachments, low bandwidth
Vertical (9:16)1080 x 1920TikTok, Reels, Shorts
Square (1:1)1080 x 1080Instagram feed posts

How to Resize Your Video

1

Upload your video

Select or drag your file. It stays local — no server upload. The tool shows your original resolution so you know what you're working with.

2

Set target dimensions

Click a preset like 1080p or 720p, or type custom width and height. Keep aspect ratio locked to avoid distortion — unless you specifically need to stretch the image.

3

Resize and download

Click resize and wait. Processing time depends on video length and resolution. Keep the tab open. When done, preview and download the resized file.

Use Cases

Meeting platform resolution limits

Some community forums and older video platforms cap uploads at 720p or 1080p. If you filmed in 4K, select the matching preset to scale the clip down to the required ceiling before you upload. The encoder remaps every frame to the smaller grid and produces a file that passes the platform check.

Standardizing clips from multiple cameras

When you receive footage from different phones and cameras for a project, each clip often has a different resolution. Type 1920x1080 into the custom fields and process each clip individually. Every file comes out at the same pixel size, which prevents resolution mismatch errors when you bring them into a video editor.

Reformatting landscape video to vertical

YouTube videos filmed in 16:9 do not fit Instagram Reels or TikTok without reformatting. Set the width to 1080 and the height to 1920, then select Cover mode. The encoder zooms the video until it fills the vertical frame and trims the left and right edges, producing a full-screen vertical clip.

Reducing file size for email delivery

Email attachments typically have a size cap between 10MB and 25MB. A one-minute 1080p recording can exceed 100MB. Resizing it to 480p cuts the pixel count by more than 75%, which reduces file size enough for most email clients to accept the attachment without a cloud link workaround.

Creating narrow banner video for websites

Hero banners on landing pages often use a custom aspect ratio like 1920x400. Turn off the aspect ratio lock and type your banner dimensions into the width and height fields. The Fill mode stretches the video to match both dimensions so it covers the banner area without black bars on any side.

Settings Explained

Width and Height Fields

These two fields define the exact output pixel dimensions. Standard HD video is 1920 pixels wide by 1080 pixels tall. Standard 4K is 3840 by 2160. You can also type any custom number here, such as 1080x1080 for a square post or 1080x1920 for a vertical reel. The preset buttons fill these fields automatically for common sizes.

Maintain Aspect Ratio

When this toggle is on, changing the width recalculates the height to preserve the original proportions, and vice versa. This prevents the video from looking squashed or stretched. Turn it off when you intentionally want to force a specific aspect ratio that does not match the source, such as converting a 16:9 clip to square format.

Fit Mode

Contain scales the video down so the entire image fits inside your target dimensions. Gaps appear as black bars. Cover scales the video up until it fills the frame completely, trimming any content that extends outside the boundary. Fill ignores the original ratio and forces the image to exactly match both your width and height values, which stretches the content.

Frequently Asked Questions

Select your video using the file picker and pick the 1080p or 720p preset button. The encoder runs entirely in your browser using your own CPU, so the file never leaves your device. Your video gets remapped to the new pixel grid frame by frame and downloads directly to your computer when done.
Contain shrinks the video to fit inside your target box while keeping the full image visible. Any empty space gets filled with black bars. Cover zooms the video until it fills the entire frame, which crops the edges. Fill ignores the original proportions and stretches the image to match your exact width and height, which can distort faces and objects.
No. Upscaling does not add detail that was never recorded. If you take a 480p clip and resize it to 4K, the encoder spreads the same limited pixels across a much larger canvas, which makes the image look blurrier. Downscaling from a higher resolution to a lower one does work well because you are discarding data rather than inventing it.
The Maintain Aspect Ratio toggle is on by default. It calculates the exact ratio between your video's original width and height, then applies that same ratio to whichever dimension you type. This prevents the video from appearing stretched or squashed when you only change one side.
Your video is never uploaded. The resizing engine runs inside your browser using WebAssembly. It reads your file from your local drive, processes it frame by frame in your device's memory, and writes the output back to your drive. No data travels over your network connection during this process.
Processing time depends on your device's CPU speed and the length of your video. A 4K video that is three minutes long can take several minutes on an average laptop because the encoder must recalculate pixel values for thousands of frames. Keep the browser tab active and avoid other heavy tasks to give the encoder as much CPU bandwidth as possible.

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