How it works

Drop in a video, such as a 9:16 vertical.
Pick the size you need, such as a 300×600 half-page display ad or a 1:1 social post.
Drag the box over the part of the video you want to keep, and use the corners to zoom in. Or choose Fit + blur to keep the whole video, or any part of it you box, with a blurred copy filling the empty space. That helps with extreme shapes like a vertical video in a 728×90 leaderboard.
Export and download an MP4 at exactly that size.

Video Reframer uses your browser's built-in video encoder (WebCodecs), so your video is never uploaded. Display ad presets drop the audio by default because those ads play muted. Check your ad network's file size limit; the Smaller file setting helps if you're over.