Convert and compress video, privately

No. DivXpress runs the conversion engine inside your browser using WebAssembly, so your video is processed on your own device. The file is never sent to us or to any server. That also means there is nothing for a third party to intercept, store, or leak, which is the point of doing it this way.

Every time a video leaves your device for a server, a copy of it exists somewhere you do not control. It can be logged, stored, scanned, or kept long after you have closed the tab. Processing on your device avoids all of that, because the bytes that make up your video never travel across the network at all. For footage of family, kids, homes, or confidential work, that distinction is the whole reason this tool exists.

Yes. Converting, compressing, and extracting audio are all free, with no sign-up, no watermark, and no cap on how many files you put through it. There is no batch queue, though: files go one at a time.

It reads common video files such as MP4, MOV, WebM, MKV, AVI and M4V, and can output MP4, WebM, MOV, animated GIF, or MP3 audio.

For the output, MP4 is the safe default because it carries H.264 video with AAC audio, the combination that plays on virtually every phone, browser, and editor. Leave the quality slider at Balanced for everyday use. Slide toward Smaller file when you need to fit an attachment or upload limit, and accept a little softness in exchange. The encoder raises the CRF value behind the scenes as you move right.

Bitrate is how many bits per second the encoder spends on the picture, and it is the main dial for file size. Quality, in this tool, is a CRF target: you tell the encoder how much detail to hold onto and it spends whatever bits each scene needs. For most people who just want a smaller file that still looks fine, the quality slider is the simpler knob.

There is no fixed limit, but because everything runs on your device, very large files depend on your available memory. Short clips and files under a few hundred megabytes are the most reliable. DivXpress does not cut clips itself, so if a long recording struggles, shortening it in whatever app it came from is the reliable fix.

The first time you convert, your browser downloads the conversion engine (about 30 MB) once and caches it. After that, conversions start immediately.