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WebM to MP4 converter, without the upload.

Turn WebM videos into MP4s that play everywhere. It is converted in your browser, so the file never leaves your device.

Drop WebM files here

or choose from your computer paste with Ctrl V

Ready · other file types work too0 bytes uploaded, ever

Convert to

How to convert WebM to MP4

  1. Add your WebM videos

    Drop WebM files onto the box above, or click it to choose them. ToAny reads the file's contents to detect the type, so a wrong extension does not matter.

  2. MP4 is already chosen

    Press Convert. Open Options first if you want to change the defaults. The work happens in this tab and can take a while for large files.

  3. Download

    Save the MP4, or download everything as one ZIP if you converted several files.

Why ToAny

  • Private by construction

    The WebM to MP4 converter is part of this page and runs inside your browser. Your videos are never sent to ToAny or to anyone else.

  • No upload, no queue

    Nothing has to travel to a server and back, so work starts the moment you press Convert. How long it takes depends on your device and the size of the file.

  • Free, without an account

    No sign-up, no email address and no watermark. Add several files and download them together as a ZIP.

WebM to MP4: what to expect

Screen recorders and browsers save WebM, and downloads from the web often arrive as WebM too. iPhones, older Safari, most TVs and video editors either refuse it or handle it badly. WebM's VP8 or VP9 video is not what those devices expect in an MP4, so the video is re-encoded to H.264.

The defaults suit most files. Under Options you can lower the resolution, trade quality against file size, remove the sound and trim the start and end. This is demanding work for a browser: a long or high-resolution file can take several minutes, and your device does all of it, so keep the tab open.

The conversion uses your browser's own video and audio codecs (WebCodecs), with hardware acceleration where the device has it; the file is read from disk as it goes and can be up to 2 GB. Where the browser lacks a codec, the page falls back to the compatibility engine. A video over 500 MB cannot be kept at full quality in browser memory; choosing a lower resolution or quality under Options lets it fit.

WebM vs MP4

WEBM

WebM video

WebM is an open, royalty-free video format built for the web. It is a restricted form of Matroska holding VP8, VP9 or AV1 video. Browsers play it; iPhones, TVs and video editors often do not.

Opens in Chrome, Firefox, Edge and recent Safari; few TVs and editors

WebM converter
MP4

MP4 video

MP4 is the video container everything plays. It normally holds H.264 video and AAC audio, a pairing that phones, browsers, TVs and social networks all accept.

Opens in Every phone, browser, TV, console and editor

MP4 converter
WebM compared with MP4
WEBMWebM videoMP4MP4 video
Stands forWebMMPEG-4 Part 14
TypeVideo containerVideo container
CompressionLossyLossy
Usually containsVP8, VP9 or AV1 video with Vorbis or Opus audioH.264 or H.265 video with AAC audio
Introduced2010, by Google2001, by the Moving Picture Experts Group
Opens inChrome, Firefox, Edge and recent Safari; few TVs and editorsEvery phone, browser, TV, console and editor
Best forRoyalty-free video on websitesSharing and uploading video anywhere
File extension.webm.mp4

Questions

Are my videos uploaded anywhere?

No. The WebM to MP4 conversion runs inside your browser, on your own phone or computer. The file is not sent to ToAny or to anyone else.

Does converting WebM to MP4 reduce quality?

It depends on what is inside the WebM. When its video and audio are already in a form MP4 can hold, they can be carried over without being compressed again. Otherwise they are re-encoded, which costs a little quality. Under Options you can favour quality or a smaller file.

Can I convert several WebM files at once?

Yes. Add as many as you like, convert them together and download each result or all of them as one ZIP.

How do I convert WebM to MP4 on Windows, Mac, iPhone or Android?

The steps are the same everywhere because ToAny runs in the web browser: open this page in a current version of Chrome, Edge, Safari or Firefox, add the WebM file, press Convert and save the MP4. There is nothing to install.

Is there a file size limit?

Yes. Files up to 2 GB are accepted, and a video over 500 MB needs a lower resolution or quality chosen under Options so the result fits in memory. Beyond that the limit is your device's memory, since nothing is uploaded; a computer copes with large files better than a phone.