Video aspect ratio and vertical crop
Crop a video to 9:16 for reels, square or 16:9, or pad it with a blurred background.
Drop the video
or click to choose (.mp4, .m4v, .mov, .webm, .mkv, .avi, .wmv, .mpg, .mpeg, .3gp, .flv, .ts, .ogv), or paste from the clipboard (Ctrl+V). Up to 100 MB per file.
Drag the frame with the mouse or move it with the arrow keys; the corners resize it.
The video is processed in your browser, nothing is uploaded. The first run downloads about 32 MB of the computing core, after that everything runs without waiting. Longer files take a few minutes.
- Runs right in your browser
- Free, no sign-up
More about Video aspect ratio and vertical crop
How changing the aspect ratio works
Upload a video, pick the target aspect ratio and decide whether to crop the picture or fill it out. When cropping, a frame appears over the video: drag it to where the action is, resize it by the corners, and nudge it with the arrow keys for fine adjustments. Filling keeps the whole shot and covers the empty space with a blurred, slightly darkened copy of the video, the look you know from Reels and news clips.
Everything runs in your browser through ffmpeg compiled to WebAssembly. The video is never uploaded; the result is produced on your computer and downloads as an MP4 with the H.264 codec, which phones, computers and every social network can play.
- 9:16 portrait for Instagram Reels, TikTok and YouTube Shorts.
- 1:1 square and 4:5 for Instagram and Facebook posts.
- 16:9 and 4:3 for YouTube, presentations and older screens, 3:4 for photo formats.
- A free ratio when you only need to cut off an edge or a watermark.
- The output size is shown before you start; it is always even, as the codec requires.
Frequently asked questions
Crop or blurred background?
Cropping gives a clean picture without distracting edges but throws part of the shot away. It suits footage where the subject sits in the middle and nothing important happens at the sides. The blurred background keeps the whole shot, so nothing is lost, but the video itself takes up a smaller part of the frame. It works well for recorded talks or videos with on-screen text that a crop would cut off.
What resolution will the result have?
When cropping, exactly as many pixels as the frame covers in the source video; nothing is upscaled, so quality only drops as much as the new encoding implies. When filling, the tool keeps the height of the video (for portrait targets) or its width (for landscape targets), so the canvas never grows beyond the source dimensions.
Is the sound kept?
Yes, the audio track is converted to AAC together with the picture. A silent video stays silent.
Why is there no preview with a frame?
Browsers cannot play every format: MKV, AVI or WMV usually fail. In that case the tool crops from the centre of the picture at the largest size the chosen ratio allows, and the blurred background mode works as normal. If you want to position the frame yourself, convert the video to MP4 first.
How long does it take?
The picture is re-encoded, and in the browser on a single thread that takes roughly as long as the video lasts. Filling with a background is a little slower because the blurred layer is computed as well. For longer recordings it helps to trim or shrink the video first.