Convert MP4 to WebM
Private by design: the conversion runs on your device. Nothing is uploaded.
- Choose the target format
- Drop your file (or click to browse)
- Download the converted file
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Output format: webm
WebM carrying VP9 is what you serve when a video should play in every browser without a licensing conversation, and it usually undercuts an equivalent H.264 MP4 by a comfortable margin. The whole clip is re-encoded here, picture and sound, into the open container. VP9 encoding is slow by design, so treat a long video as a job you start and leave running.
Frequently asked questions
- How long will a clip take to convert?
- Longer than real time on most machines, because VP9 performs considerably more analysis per frame than H.264 does. A one minute clip is a coffee, a twenty minute one is an afternoon.
- Is WebM a good choice for social media uploads?
- Rarely. Most platforms still want an MP4 and will transcode anything else you give them. WebM earns its place on video you host and serve yourself.
- What happens to the audio track?
- It is re-encoded to Opus, the codec WebM pairs with VP9. Browsers decode that natively, so nothing extra is needed on your page.