Free Online WebM to MP4 Converter

Convert WebM files to MP4 here, free, for video that plays on every device.

Video & Audio Converter

Free & Private: We do not store your data.

Convert WebM to MP4 in your browser

Your file never leaves your device.

Drag and drop, or
Opens
MP4MOVWebMMKVTSMP3WAVM4AAACOGGFLAC
Saves as
MP4WebMMOVMKVMP3M4AWAVFLACOGG

Up to 500 MB per file.

Results are provided for informational purposes only and may contain errors. Please verify important information independently. Use of this tool is at your own risk.

How to convert WebM to MP4

  1. Drop your WebM file on the box above or click the box to choose it.
  2. MP4 is already selected. Pick a quality, and trim the start or end if you need to.
  3. Click Convert and watch the progress bar. Files that can be copied without re-encoding are ready in seconds.
  4. Click Download to save the MP4 file.

Why convert WebM to MP4?

WebM is an open video format made for the web, usually with VP9 or VP8 video and Opus sound. Browsers play it, but many phones, TVs and editing programs don't.

MP4 is the most widely supported video format. With H.264 video and AAC sound it plays on every phone, computer, smart TV and website, and every social network accepts it.

Choose MP4 when the video has to play everywhere or be uploaded to a website or social network.

WebM and MP4 at a glance

FormatWebMMP4
TypeVideoVideo
CompressionLossyLossy
Typical codecsVP9 / VP8 / AV1 + OpusH.264 / H.265 + AAC
Best foran open format for web videovideo that plays on every device
Opens inAll current browsersEvery device and app

Good to know

  • WebM usually holds VP9 or VP8 video. It is re-encoded to H.264 where your browser can, so the MP4 plays on phones and TVs; that takes longer than a simple copy.

Questions about converting WebM to MP4

Is the WebM to MP4 converter free?

Yes. It is free, with no sign-up, no watermark and no limit on how many files you convert.

Is my file uploaded?

No. Your browser reads and converts the file on your own device; nothing is sent to 4Dev or anyone else.

Is there a size limit?

Files can be up to 500 MB. The result is built in your device's memory, so very large files are better converted on a computer than on a phone.

Will converting to MP4 reduce quality?

MP4 is lossy, so it drops detail that is mostly inaudible or invisible. The default settings are a good balance; choose a higher quality or bitrate for archiving.

Which browsers can do this?

Current Chrome, Edge, Safari and Firefox on a computer, and Chrome or Safari on a phone. The format list only offers what your browser can actually create.

Is this tool free?

Yes, it's free to use. No signup, no email required. Get results on this page.

How do I get my result?

Use the tool on this page. Your result appears here; no email delivery is required.