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Change Video Aspect Ratio

Drop in a clip and pick the shape you need — 9:16 for TikTok, Reels and Shorts, 4:5 or 1:1 for the Instagram feed, 16:9 for YouTube, or any ratio you type in. Crop to fill the frame and drag to choose what stays, pad it with a colour, or sit it on a blurred copy of itself. The whole re-encode happens in your browser: free, no watermark, no signup.

Your video is reframed on your own device — nothing is uploaded to a server.

Upload or Select File

MP4, MOV, WebM, MKV and AVI, up to 2 GB. The file stays on your device.

How to change a video's aspect ratio

Three steps, no account and no upload

  1. 01

    Drop in your video

    Drag in an MP4, MOV, WebM, MKV or AVI file. It is read straight from your disk — nothing is sent anywhere.

  2. 02

    Pick the shape and the fit

    Tap TikTok, Reels, Shorts or any ratio you like, then choose crop, colour bars or blur fill. Drag the preview so it is the background that gets cut, not your subject.

  3. 03

    Convert and download

    Your browser re-encodes the clip to MP4 at the new size and shows the before and after. No watermark, ready to upload.

Free Video Tools

Free Tools

Frequently Asked Questions

Yes. No account, no trial, no export cap and no watermark burned into the file you download. Convert as many clips as you like — the only real ceiling is how much memory your device has.
No. The file is read from your disk with the browser's File API and re-encoded with WebCodecs on your own machine. If you want to check, open DevTools, switch to the Network tab and convert a clip: you will not see a single request carrying your video.
MP4, MOV, WebM, MKV and AVI go in, as long as your browser can decode what is inside — that covers H.264, HEVC on most Macs, VP9 and AV1. What comes out is always an MP4 with H.264 video, which is the file TikTok, Instagram and YouTube all accept without arguing. The audio track is carried straight across whenever the container allows it.
Up to 2 GB. Past roughly 500 MB it warns you first, because the output is assembled in memory: a 1 GB source is fine on a laptop with plenty of RAM and may not be on an older phone. Long 4K clips are the hardest case — choosing a 720p output makes a big difference there.
Crop fills the new frame and throws the rest away: 16:9 to 9:16 discards about two thirds of the picture, which is exactly why you can drag the preview to say what stays. Pad and blur fill keep every pixel and fill the leftover space instead — flat colour for a clean look, a blurred copy of the frame for the style Reels and Shorts made standard. The tool shows you the percentage before you commit to a crop.
The picture is decoded and encoded again, so yes, it is lossy — but the bitrate is set generously and capped at what the source already carried, so the change of shape is meant to be the only thing you can see. Your device's hardware encoder does the work through WebCodecs, which is why a one-minute clip takes seconds rather than minutes.
Not here, and not in any browser tab: the pixels outside the original frame were never recorded, so extending them means inventing them. That is what an AI video model is for — it generates in 9:16, 16:9 or 1:1 natively rather than reshaping something that was shot the other way round. If a full vertical frame is what you actually need, it is better to generate it than to crop into it.
One clip at a time, on purpose: decoding and encoding are memory-hungry, and a browser tab running a batch is the fastest way to crash it. When one is done, press "Convert another". It does work on phones — recent iOS and Android Chrome both ship WebCodecs — but keep clips short there, and keep the tab in the foreground while it runs.

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Show more (+12)
  • Video to Video
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  • More Camera Movement
  • Private Video Visibility
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