Skip to content
NewMastershot Studio is open: a video editor with no watermark on anything you export. Try it free

Change aspect ratio

Turn a video vertical, square, or widescreen without cutting anything off, or crop it to fill the new shape. Processing stays on your device.

Files stay on your device

Drop a video to reshape

Choose 9:16, 1:1, 4:5, or 16:9, then keep the whole picture on a blurred background or crop to fill.

Any media file this browser’s engine can read.

How to change a video’s aspect ratio

Pick 9:16 for Shorts, Reels, and TikTok, 1:1 or 4:5 for the Instagram feed, or 16:9 for YouTube. Keep the whole picture on a blurred or black background, or crop it to fill the frame. This aspect ratio converter runs in your browser, so the video is never uploaded.

  1. Step 1

    Choose a video
    Pick the video you want in a new shape.

  2. Step 2

    Choose the shape
    Pick 9:16, 1:1, 4:5, or 16:9, then bars or a crop.

  3. Step 3

    Download the video
    Export it at the new aspect ratio.

What to expect

Supported inputs
Any media file this browser’s engine can read.
What happens
The video is re-encoded in its source format at the new shape. With bars, the frame keeps the source’s short side, so a 1080p video becomes 1080 × 1920 for 9:16. With a crop, the chosen area is kept at its own resolution.
Limits
A video track is required, and subtitle tracks are left out. Frames are kept within 3840 × 2160, which browser encoders handle.

Private by design

Your video stays on your device

Mastershot processes your file locally in this browser. It does not need to be uploaded to a server, and you do not need an account to use the tool.

  • No upload
  • No signup
  • No watermark

Questions

9:16, vertical, at 1080 × 1920 pixels. Choose 9:16 to turn a landscape video into a Short without losing its edges.

Reels and Stories are 9:16 (1080 × 1920). Feed posts can be square, 1:1 (1080 × 1080), or portrait, 4:5 (1080 × 1350), which takes up the most room in the feed.

Choose 16:9. Bars keeps the whole picture in the middle with a blurred or black background on the sides; Crop keeps a 16:9 slice of the frame, which you can drag into place.

Bars keeps everything in the shot and is right for text, faces near the edges, and screen recordings. Crop fills the screen but cuts off the sides, so it suits a subject that stays near the middle.

Related tools