Convert · MP4 → WebM
Convert MP4 to WebM — right in your browser
Drop an .mp4 and get a .webm — the open format built for the web, often smaller at the same quality. It's converted on your own device and never uploaded.
Why convert MP4 to WebM?
WebM is the open, royalty-free format designed for the web. It tends to be smaller than MP4 at similar quality and is ideal for background videos, HTML5 <video> and places where you want a lightweight, license-free file.
Most converters upload your clip to a server first. VidKit doesn't — the conversion runs locally in your browser. WebM uses the built-in software engine, so it's slower than the MP4 fast path, but nothing is ever stored or logged.
Frequently asked questions
Is my .mp4 file uploaded anywhere?
No. The conversion happens entirely in your browser, on your own device. There's no server that could receive the file — watch your browser's Network tab while it runs and you'll see zero bytes leave.
Why does WebM take longer?
WebM uses a software encoder that browsers can't hardware-accelerate for output, so it's slower than converting to MP4. Keep clips short for the quickest results.
Will it play everywhere?
WebM plays in all modern browsers and on Android, but not on every older device or in some editors. If you need maximum compatibility instead, convert to MP4.