Compress a video without uploading it

Ten minutes of phone footage is easily 800 MB, and then it fits neither into an email nor past an upload limit. This makes it smaller — in your browser, no account, no upload. The file never leaves your device.

How the shrinking works

The video is re-encoded to H.264 at 1080p or less, the audio to 128 kbit/s AAC. The target bitrate is not fixed but follows resolution and frame rate — roughly 0.1 bit per pixel per frame. A fixed bitrate would inflate a small video instead of shrinking it.

Encoding runs through WebCodecs, meaning your device's video chip rather than JavaScript. That is the only reason it is fast enough to do in a browser at all. Chrome and Edge handle it, recent Safari too.

If a file is already packed well, nothing happens: it is left alone, because re-encoding would only cost quality.

What happens to your file

Nothing. There is no upload and no server call. Close the tab and it is all gone. The same encoding runs inside Caption & Cut before a video is uploaded — this tool is that single step on its own.