MP4 to WebM
Upload an MP4 file and convert it to WebM, the open format preferred by web standards. The tool encodes video with VP9 (high-quality, royalty-free) and audio with Opus (the best lossy audio codec available). The result plays natively in all modern browsers without plugin or codec concerns.
WebM is useful for web embedding where open standards matter, for platforms that prefer or require WebM, or when you want to avoid H.264 licensing considerations. The VP9 codec typically achieves similar quality to H.264 at comparable file sizes.
Everything runs in your browser using ffmpeg.wasm — your video is never uploaded to a server.
By The Paper Room Editorial Team — Video Tools
Frequently asked questions
Why convert to WebM?▼
WebM uses royalty-free codecs (VP9 video, Opus audio) and is the preferred format for open web standards. It plays natively in Chrome, Firefox, and Edge. It's useful when you want to avoid H.264/AAC licensing or when a platform requires WebM.
Is WebM quality comparable to MP4?▼
Yes. VP9 (the video codec used in WebM) achieves similar quality to H.264 at comparable bitrates. For most content, you won't notice a quality difference between the original MP4 and the WebM conversion.
Will the WebM play on iOS?▼
Safari added WebM/VP9 support in iOS 15 and macOS Monterey. Older Apple devices may not play WebM natively — in that case, MP4 with H.264 is the safer choice.