VideoCompress

VideoCompress shrinks a video to a target size in MB entirely inside the browser tab. The file is never uploaded — WebCodecs does the encoding on the device, and ffmpeg.wasm covers the formats WebCodecs cannot decode.

MP4, MOV, WebM, MKV, AVI, WMV and FLV go in. There is no file-size limit, no watermark, no account and no queue, because there is no server doing the work.

The site also publishes its own measurements: three real files put through the tool, with source bitrate, the size the tool predicted, the size that actually came out, and what each test does not prove.