Resize a video
Change a video's resolution by entering precise dimensions (in pixels) or an enlargement/reduction percentage. Processing happens entirely in your browser, with no upload to a server.
How it works
The tool loads a video processing engine (ffmpeg compiled to WebAssembly) into your browser and applies a scaling filter to the picture, without ever sending your file to a server. The audio track is kept as is.
What happens if I set an odd width?
Common video codecs require even dimensions. In "keep aspect ratio" mode, the height is calculated automatically and rounded to the nearest even number; in percentage mode, both dimensions are rounded the same way to avoid any encoding error.
Does scaling up reduce quality?
Yes: enlarging a video beyond its original resolution (for example to 200%) doesn't create extra detail, so the picture will just be bigger but blurrier. Scaling down (for example to 50%) generally gives a sharp result.
Your videos never leave your device: resizing is computed entirely locally, via WebAssembly, with no network transfer of the file.