Simple online media conversion

WebM converter.

Convert WebM for browsers, or out to MP4 for sharing.

Drop a video file here

or choose a file from your device

MP4 · MOV · WebM · MKV · AVI · M4V and more

About WebM

Convert WebM for browsers, or out to MP4 for sharing. Justvert keeps this page focused on one format so you can convert into or out of WebM without hunting through a long list of obscure options.

The Strategy Engine still inspects the source. Compatible H.264 streams remux. Hardware-friendly transcodes use WebCodecs. Legacy containers fall back to FFmpeg WASM.

WebM converter FAQ

What is a WebM converter?

A WebM converter changes a media file into or out of the WebM format. On Justvert you drop a file, pick WebM or a related output, and convert in the browser.

Which files can I convert with the WebM converter?

The WebM converter accepts common video and audio inputs such as MP4, MOV, WebM, MKV and AVI when the source is a media file. Use Auto detect if you are unsure of the input format.

Does Justvert upload my files to a server?

No. Conversion runs locally in your browser. The chosen file is read on the page, processed by remux, WebCodecs or FFmpeg WASM, then written back with a WritableStream or a download. Source files are not uploaded to a Justvert conversion server.

Do I need to install software to convert a video?

No. Justvert is an online video converter. Open a modern web browser, drop a file, and convert. There is no desktop app or browser extension to install.

Will converting a video reduce its quality?

It can, if the file has to be re-encoded. Compatible H.264 plus AAC streams can be remuxed into MP4 without touching the pictures or the sound. WebCodecs and FFmpeg paths re-encode and may introduce some quality loss depending on the source and output size.

When should I keep WebM instead of converting?

Keep WebM for browser playback and efficient web delivery. Convert to MP4 when you need the clip in a phone gallery, an editor or a messaging app.