Is this tool really free?

Yes, 100% free with no limits, no signup, and no watermarks.

Does my file get uploaded to a server?

No. Everything runs locally in your browser — your file never leaves your device.

MP4 is the most widely supported video format across browsers, phones, and editing software.

WebM to MP4 runs entirely in your browser. Enable JavaScript to use the interactive tool — your files are processed locally and never uploaded.

WebM to MP4 uses FFmpeg via WebAssembly to transcode modern WebM browser videos into the universally supported MP4 format.

Yes, 100% free with no limits, no signup, and no watermarks.
No. Everything runs locally in your browser — your file never leaves your device.
MP4 is the most widely supported video format across browsers, phones, and editing software.