Re-encode your video to H.264+AAC (MP4) in the browser. Quality preset or target bitrate. Nothing is sent to a server.
Compress a video to a smaller file. The tool re-encodes your clip to H.264 video and AAC audio in an MP4 using ffmpeg compiled to WebAssembly, with a quality (CRF) or target-bitrate setting.
Choose a quality/CRF setting when you care about consistent visual quality and are flexible on size, or a target bitrate when you must hit a specific file size. Re-encoding is computation-heavy, so long, high-resolution clips take longer than short ones.
No. The clip is re-encoded to H.264/AAC by ffmpeg compiled to WebAssembly, inside this browser tab, your video is read into memory on your own device, compressed there, and the smaller MP4 is offered as a local download. Nothing reaches Sunasty or any third party. Open your browser DevTools, go to the Network tab and watch: no request carries your video.
Re-encoding is computation-heavy and runs on your own device, so the time depends on the clip length, resolution and your hardware. Shorter clips finish quickly; long, high-resolution videos take longer because nothing is offloaded to a server.
Use a quality/CRF setting when you care about consistent visual quality and are flexible on size; use a target bitrate when you must hit a specific file size. Both run locally.
Yes, after the page and the ffmpeg engine have loaded once. The encoding itself then runs on your device without the network.
It is completely free and requires no sign-up. There are no watermarks, no daily limits and no tracking cookies needed to use the tool.