How to use it
- Upload your MP4 file, or paste a link to it.
- Choose Convert.
- WebM is already selected as the output.
- Press Convert.
- Download your WebM file.
Features
No full download needed
When the source supports it, we fetch only the part of the file we actually need. A 40-second clip from a two-hour video transfers roughly 40 seconds of data, not two hours.
Private by default
No sign-up, no tracking of what you process, and automatic deletion. Your links are never sent to analytics and your files are never made public.
Built for phones
Large touch targets, a timeline you can actually drag with a thumb, and a sticky action button. Works in Safari on iPhone and Chrome on Android without an app.
How it works technically
We probe the MP4 file first to see which codecs it contains. If they are valid inside WebM, FFmpeg rewrites the container with -c copy and the compressed picture data is untouched. Otherwise we re-encode to H.264 and AAC, which is the combination with the widest device support.
Frequently asked questions
Does converting MP4 to WebM lose quality?
A re-encode is required here, so there is some loss in theory. We use quality-targeted settings so it is not visible in normal viewing.
What happens to my file after processing?
It is deleted automatically. Your result is stored in a temporary folder for a short window so you can download it, then removed permanently along with any intermediate files. We do not publish, index, share or keep your media, and we never use it to train AI models.
Do I need to install any software?
No. Everything runs in your browser and on our servers, so it works the same on Windows, macOS, Linux, Android and iPhone. There is no app to install and no account to create.
Can I process any video I find online?
Only content you own or are otherwise permitted to process. The service works with publicly accessible links and does not bypass DRM, paywalls, sign-in or any other access control. You are responsible for having the rights to the material you submit.