Is WebM to MP4 free? Is there a watermark?

Yes — WebM to MP4 is free to use with no sign-up or watermark. Very large files can still be limited by your browser's available memory and processing resources.

Do my files get uploaded to a server?

No. WebM to MP4 runs entirely in your browser with WebAssembly, so your WebM file never leaves your device and nothing is stored or seen by us.

What can I put in, and what do I get out?

WebM to MP4 accepts WebM and gives you back a MP4 file. Actual codec support depends on what the bundled engine or browser decoder can read.

Will I lose quality converting to MP4?

The H.264 conversion is lossy rather than a reversible container change. Keep the source and compare motion, fine text, colour, and audio sync in the result.

Free tools · Convert

WebM to MP4

Convert a WebM video into H.264/yuv420p MP4 with AAC audio for broader editor, messenger, and social-platform compatibility. Everything runs locally in your browser.

Runs entirely in your browser. Your file is never uploaded — no watermark, no account.

Drop a file or click to chooseWebM

Get a better result

Best for: Browser recordings and downloaded WebM files that must open in an MP4-only editor, messenger, presentation tool, or publishing workflow.
Input → output: WebM video is decoded and re-encoded as fast-start H.264/yuv420p MP4 with 128 kbps AAC audio rather than copied between containers.
Quality tip: Inspect rapid movement and screen text because already-compressed WebM detail can soften during a second lossy encode. Keep the source for comparison.
Know before running: Quality cannot exceed the original, and unusual WebM codecs may not decode in the bundled engine. Extra tracks and metadata are not exposed for selection or preservation.
Next step: Trim video to remove unwanted recording time from the new MP4.

How to use WebM to MP4

1
Choose your file. Drop a supported WebM file into the tool, or click to select one. It stays on your device — nothing is uploaded.
2
Run locally. Press Run to begin. The first processing run loads the browser engine before local processing begins.
3
Download. Review the result, then download the finished file from your browser with no watermark.

Frequently asked questions

Is WebM to MP4 free? Is there a watermark?: Yes — WebM to MP4 is free to use with no sign-up or watermark. Very large files can still be limited by your browser's available memory and processing resources.
Do my files get uploaded to a server?: No. WebM to MP4 runs entirely in your browser with WebAssembly, so your WebM file never leaves your device and nothing is stored or seen by us.
What can I put in, and what do I get out?: WebM to MP4 accepts WebM and gives you back a MP4 file. Actual codec support depends on what the bundled engine or browser decoder can read.
Will I lose quality converting to MP4?: The H.264 conversion is lossy rather than a reversible container change. Keep the source and compare motion, fine text, colour, and audio sync in the result.