Resize your video to new dimensions or crop it to a different aspect ratio. Works instantly in your browser — no upload, no account needed.
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Choose Video FileMP4, WebM, MOV · Max 100MB
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This tool resizes a video to new dimensions, or crops it to a different aspect ratio — useful for fitting a video to a specific platform's requirements, such as converting a widescreen video to a square or vertical format for social media.
Processing happens entirely in your browser using a built-in video processing engine — your video is never uploaded to a server. The first time you use any of our video tools, there's a one-time download of this processing engine (around 30MB), cached afterward for instant use. Because resizing and cropping require re-encoding, this can take some time depending on your video's length.
Resizing scales the entire video to new dimensions — if the new dimensions have a different aspect ratio than the original, the video will appear stretched or squashed unless padding is added. Cropping cuts away parts of the frame to change the aspect ratio without stretching — for example, cropping a 16:9 video to 9:16 keeps the centre portion and removes the sides, producing an unstretched vertical video at the cost of losing the cropped-out content.
For platforms that expect vertical video (9:16) when your source is widescreen (16:9), cropping to the centre often works well if the important content (like a person speaking) is centred in frame. If important content is near the edges, cropping may cut it off — in that case, resizing with padding (adding bars to maintain the full frame within a different aspect ratio) preserves everything but adds visible borders.
If you're filming content with the knowledge that it will need to work in multiple aspect ratios — for example, the same video repurposed for a widescreen YouTube upload and a vertical Instagram Reel — it's worth thinking about framing during filming itself rather than only at the editing stage. Keeping important subjects (a speaker's face, a key action) closer to the centre of the frame, with some margin on the sides, gives you more flexibility to crop to a narrower ratio later without losing anything important. Footage filmed "tight" — with subjects already close to the edges of a widescreen frame — leaves much less room for a vertical crop without cutting something important out, often forcing a choice between cropping awkwardly or using the padding approach with visible bars.
Beyond aspect ratio changes, resizing to a smaller resolution (for example, from 4K down to 1080p, or from 1080p down to 720p) is one of the most effective ways to reduce a video's file size, often more impactful than compression settings alone. This is particularly relevant for footage shot on modern phones, which often record at much higher resolutions than necessary for how the video will actually be viewed — a video that will only ever be watched on a phone screen or in a small embedded player doesn't benefit much from 4K resolution, but does benefit from the significantly smaller file size that comes with downscaling to 1080p or even 720p. If file size or upload time is a concern and the video's resolution is higher than its intended viewing context requires, downscaling before further edits can make every subsequent processing step faster too, since there's less data to work with.
If you only need to trim the video's length rather than its dimensions, use Video Trimmer. To reduce file size after resizing, see Video Compressor.
If the new dimensions have a different aspect ratio than the original, resizing alone will stretch or squash the image. Cropping avoids this by cutting the frame instead of stretching it.
Cropping is centred — equal amounts are removed from each side (or top and bottom) to reach the target aspect ratio.
Resizing and cropping require re-encoding every frame, which is more computationally intensive than operations that can copy data directly.
Files up to 100MB are supported. Larger or longer videos take proportionally longer to process.
No, processing happens entirely within your browser.