Video Aspect Ratio Online

Upload a video, choose a target aspect ratio and padding background, then process and download the result.

1. 1

   Add video

   Drop a video file or click to browse.

2. 2

   Choose ratio

   Pick 16:9, 9:16, 1:1, 4:5, 4:3, 3:4, 21:9, 2:3, or type your own.

3. 3

   Fit or fill

   Keep the whole picture with bars, or fill the frame and crop the edges.

4. 4

   Choose padding background

   Select blur, black, solid color, image, or mirror edges.

5. 5

   Choose output format

   Select MP4, WebM, or MOV.

6. 6

   Process and download

   Apply the aspect ratio and download.

Different platforms use different aspect ratios: 16:9 for YouTube and TV, 9:16 for TikTok and Reels, and 1:1 for some Instagram posts. This tool converts to the chosen ratio by letterboxing (fit with padding) so nothing is cropped.

Change the aspect ratio to 16:9, 1:1, 9:16, and more with letterbox padding and no cropping.

Compatible video in and out. Pick target ratio and padding style, preview, export in a compatible format, private processing.

• 16:9, 1:1, 9:16 & more · Letterbox, no crop
• MP4, WebM, MOV output

Benefits

• Platform-ready: Match 16:9, 9:16, 1:1, 4:3, or 3:4 for major platforms.
• No cropping: Letterboxing keeps the entire image; padding fills the rest.
• Blur background: A popular Reels look that avoids harsh black bars.
• Format choice: Export MP4, WebM, or MOV while preserving quality.

Every aspect ratio change has to resolve the same conflict — your video is one shape and the target is another. There are exactly two honest answers, and this tool offers both. Fit keeps every pixel of the picture and makes up the difference with bars. Fill crops the edges away so the frame is covered corner to corner. Which one is right depends on whether the edges of your shot carry anything you need.

Choosing between them

• Fit (keep it all): Nothing is cut off. Use it when the shot is framed tightly, when text or faces sit near an edge, or when you want the blurred-background look that reads as deliberate rather than as an accident.
• Fill (crop to edge): No bars at all. Use it when the subject sits in the middle and the edges are just room — a talking head, a centred product, a screen recording with margins.
• Zoom, on either one: Push the picture larger inside the frame. On fit it shrinks the bars until they disappear; on fill it crops in tighter on the subject.
• Which part survives: The nine-way position control decides which edge is kept when the picture is cropped, and which side the bars sit on when it is not. A subject standing on the left of a wide shot stays in frame if you anchor left.

When the video doesn’t fill the target frame, you can choose how to fill the bars for a polished look.

Available options

• Blur background: Fill padding using a blurred version of the frame. Adjust blur strength.
• Solid color: Use any color (default black) for consistent branding.
• Image background: Upload an image to fill padding behind the video.
• Mirror edges: Extend the frame using mirrored edges (no extra assets).
• Black: Classic letterbox bars—simple and neutral.

Choose the ratio that matches your target platform or use case.

Available ratios

• 16:9 (Landscape): Widescreen for YouTube, TV, and desktop playback.
• 9:16 (Portrait / Reels): Vertical for TikTok, Reels, and Stories.
• 1:1 (Square): Square for some Instagram feed posts.
• 4:3 (Standard): Traditional ratio used in older TV and cameras.
• 3:4 (Portrait): Portrait ratio used for some social and mobile layouts.

Changing an aspect ratio does not add detail to a video, so this tool never enlarges one. The output size is worked out from the video you gave it: the target shape decides the proportions, your video's own long edge caps the size, and the output-size control can only pull that number down further. A 640-pixel-wide clip set to 16:9 comes out 640 wide, not stretched up to 1920.

What that means in practice

• Nothing is upscaled: A small clip stays small. Enlarging it would multiply the file size while adding no detail at all, and it is the most common way an aspect-ratio tool quietly makes a video worse.
• Round, expected sizes: A 1080p clip set to 9:16 comes out 1080×1920, and set to 16:9 comes out 1920×1080 — the sizes the platforms actually ask for.
• The bitrate follows the frame: The rate is read from your video's own track and scaled by how the frame changed, so a smaller output really is a smaller file instead of being padded back up to the original rate.
• Free and Pro: Free exports up to 720 pixels on the long edge. Pro goes up to whatever your device can handle, and both are ceilings — neither ever enlarges your video.

The tool letterboxes your video: it scales the image to fit inside the target aspect ratio and adds padding so the output has the exact ratio without cropping.

Processing steps

• Scale to fit: Frames are scaled to fit inside the target dimensions without stretching.
• Letterbox & padding: Padding is added as needed; you choose blur, black, solid color, image, or mirror edges.
• Re-encode & output: Frames are encoded to MP4/WebM/MOV with optional bitrate preservation.

Powered by optimised video encoding pipelines.

• Video compressor
• Video resizer
• Rotate video
• Flip video
• Video to GIF
• Video cropper