MP4 to WebM
To convert MP4 to WebM, choose the MP4 file and press Convert. Nolo re-encodes the video to VP9 and the sound to Opus on your device, or copies them if they are already in those formats.
- ๐ Runs on your device
- โค 0 bytes uploaded
- ๐ด Works offline
- โ Free, no sign-up, no watermark
- โฌ 0.7 MB engine, first use only
How to use MP4 to WebM
- Choose your MP4 videos.
- Press Convert.
- Wait while the video is re-encoded on your device.
- Download the WebM.
Is it private?
Yes. MP4 to WebM runs entirely in your web browser using your device's own processor. Your files are never uploaded to Nolo or anyone else, and the page cannot send them anywhere: its security policy only allows it to talk to nolotools.com, which has no place to receive files. Results are kept encrypted on your device for 60 minutes in Your files, then deleted automatically, or straight away with Delete all. How Nolo works.
Questions and answers
Are my videos uploaded?
No. Everything happens inside your browser with its built-in media engine (WebCodecs). Your videos never leave your device, and the page works offline once loaded.
Why use WebM?
WebM is an open, royalty-free format that every modern browser plays. VP9 often gives smaller files than H.264 at the same quality, which helps web pages load faster.
Which codecs are used?
VP9 video (VP8 if your browser cannot encode VP9) and Opus audio.
Why is it slower than MOV to MP4?
MP4 usually holds H.264, which WebM cannot contain, so the video has to be re-encoded rather than copied.
Does Safari play WebM?
Recent Safari versions play VP9 WebM on most Apple devices, but for the widest support keep an MP4 version as a fallback.