Change Video Aspect Ratio
VideoDrop a video, pick the shape the platform wants, and choose how the empty space is filled.
Every platform wants its own shape: 9:16 for Reels, Shorts and TikTok, 1:1 or 4:5 for a feed, 16:9 for YouTube and most screens. Changing the aspect ratio of a video means deciding what fills the difference. Cropping to fill is quick but loses the edges — and often the person at the side of the frame. The alternative keeps the whole picture and fills the space around it, either with a blurred, darkened copy of the video itself, which is how most phone apps do it, or with a solid colour of your choice. You see the result before you commit. The video is re-encoded on your device, in real time, with no watermark and no upload.
Need a different limit? Aspect Resizer takes any target, in KB or MB — whatever the form asks for.
Why do it here
100% private
Your video files are processed locally and never uploaded.
Instant
No upload or download wait — it runs at the speed of your device.
Free to start
Use it free every day; go Pro for unlimited runs.
No install
Works in any modern browser. No sign-up to begin.
How it works
- 1Drop your video
MP4, MOV or WebM.
- 2Choose the shape and the fill
9:16, 1:1, 4:5 or 16:9 — then blurred background, a solid colour, or fill by cropping.
- 3Press Change aspect ratio
It re-encodes on your device as the video plays, and downloads when it finishes.
Frequently asked questions
Will it crop my video?
Only if you choose Fill. Blurred background and Solid colour keep the whole picture and fill the space around it, so nothing at the edges is lost.
Why does it take as long as the video?
The browser re-encodes the video in real time as it plays. A one-minute clip takes about a minute; you can stop at any point.
Is there a watermark?
No. The video comes back with nothing added but the new frame.
Is my video uploaded?
No. It is reframed and re-encoded in your browser, on your own device.