Drop videos, or browse
Select several at once to convert them into a ZIP.
avi · flv · mov · mp4 · mpeg · ogg · webm · wmv & more
Choose a video from your device or drag it straight into the browser window.
Use the options dialog, where WebM is the target; set an optional resolution or enable compression if you want an even smaller file.
Click Convert to kick off the VP8 and Opus encoding.
Monitor the on-screen percentage that overlays your video preview.
Save happens automatically: the WebM downloads as soon as it is finished.
WebM is the video format designed for the open web. Built on royalty-free codecs, it delivers good quality at small file sizes and plays natively in Chrome, Firefox, Edge, and modern Safari, making it a strong choice for videos embedded directly in web pages. This tool converts MP4, MOV, AVI, MKV, and other formats to WebM using the VP8 video codec with Opus audio.
Web developers reach for WebM when adding background videos, product demos, or short loops to a site, since lighter files mean faster page loads. It is also a sensible pick for publishing on platforms that favor open formats, or simply for shrinking a clip without giving up much visual quality.
100% private“This converter never phones home with your content. Encoding to WebM takes place wholly inside the browser via WebAssembly FFmpeg, so your original video and the converted result exist only on your own hardware.”
Video is encoded with VP8 and audio with Opus, both royalty-free and open. That means anyone can play or serve the files without licensing fees, which is a core reason WebM became popular on the web.
Pick WebM when the destination is a web page and you care about small file sizes with open codecs. Pick MP4 when the video must play on the widest possible range of devices, including older TVs and mobile apps.
All major desktop browsers support it, and recent versions of Safari on Mac and iPhone do as well. Older Apple devices and some smart TVs may still struggle, so sites often serve an MP4 fallback alongside WebM.