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GroovyConvert

MP4 to WebM Converter

Convert MP4 to WebM online in seconds, for free and with no watermark. Nothing is uploaded: the conversion runs in your browser.

Drop Files Here

or

You can also paste with Ctrl + VNothing is uploaded or stored

0 bytessent to any server

Your files stay yours

Files are converted inside your browser. They are never sent to a server and we don’t keep any copy. Everything is wiped from memory when you clear the list or close the tab.

How It Works

  1. 1

    Drop your MP4 files, choose them or paste them.

  2. 2

    They are converted to WebM automatically, right on your device.

  3. 3

    Download them one by one or all together in a ZIP.

What is MP4?

MP4 is the most compatible video format: it plays on every phone, browser, TV and social network. It usually holds H.264 or H.265 video and AAC audio.

What is WebM?

WebM is an open video format created for the web, with VP9 or AV1 video and Opus audio. It’s what many screen recorders and browsers produce, but some editors and Apple devices don’t open it.

More MP4 Conversions

Convert Other Formats to WebM

Questions

Does converting MP4 to WebM lose quality?
When the audio and video already fit in WebM, they are copied as is, without any loss and almost instantly. Otherwise they are re-encoded at the quality you choose (high by default), and the difference is hard to notice.
Do you store my files?
No. Your files are never uploaded, so there is nothing for us to store. They only exist in your browser’s memory while the page is open and are deleted when you remove them, clear the list or close the tab. We only count anonymous usage, like how many conversions happen, never file names or contents.
Is it safe?
Yes. Your files are converted on your own device and are never uploaded to any server.
Is it free?
Yes. It’s free, with no sign-up, no watermarks and no ads.
Is there a limit?
We don’t set any limit on the number or size of files. Since everything happens on your device, its memory is the real limit: on a computer, 100-megapixel photos, 300-page PDFs and long videos convert without trouble. Phones have less room. Video and audio use your browser’s codecs, so Chrome and Edge support the most formats. If something doesn’t work, we’ll tell you.
Does it work on my phone?
Yes, in any modern browser on iPhone, Android or desktop.