MP4 to WebM Converter
Convert MP4 video files to WebM format online. WebM is optimized for the web.
About this tool
Convert MP4 video files to WebM format online. WebM is optimized for the web. This tool runs entirely in your browser — no file upload, no account required, and no data is ever sent to a server. Video conversion is powered by FFmpeg compiled to WebAssembly, running entirely inside your browser tab.
- ✅ Free to use, no sign-up required
- ✅ Files never leave your device
- ✅ Powered by WebAssembly — no plugins needed
- ✅ Works on any browser and device
How it works
FFmpeg (compiled to WebAssembly) handles the video transcoding entirely in your browser. Your video is decoded from the source format and re-encoded into the target format. Depending on file size, processing may take a moment.
Frequently Asked Questions
Is MP4 to WebM Converter free to use?
Yes, MP4 to WebM Converter is completely free. There are no usage limits, no sign-up required, and no hidden fees.
Are my files safe when using this tool?
Completely. All processing happens locally in your browser using JavaScript and WebAssembly. Your files are never uploaded to any server and never leave your device.
Does MP4 to WebM Converter work on mobile?
Yes, MP4 to WebM Converter works in any modern browser including mobile browsers on iOS and Android — no app installation required.
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