WebM to MP4 Converter
Turn WebM clips into H.264 MP4 files that editors, phones and social apps accept. The conversion happens entirely in your browser — your video is never uploaded.
WebM plays in browsers — and almost nowhere else
WebM is an efficient open format, which is why browsers love it and why screen recorders and capture extensions save it by default. Step outside the browser, though, and support falls away: video editors ask for MP4, phones refuse the file, and upload forms reject the extension. Converting with the video to MP4 converter on this page rewrites the clip as H.264 MP4, the format with the widest support across editors, devices and platforms.
What changes during conversion
The converter decodes the WebM stream and encodes a new MP4, respecting the maximum resolution you choose and never upscaling. H.264 encoding is lossy, so the output is a faithful copy rather than an identical one — for typical screen recordings and downloaded clips the difference is negligible. Audio is preserved as AAC; embedded subtitles are not copied. If your source is a different container, the same tool covers MOV to MP4, MKV to MP4 and AVI to MP4 with the same local engine.
No upload, no waiting room
Server-side converters make you upload the whole clip and wait in a queue. Here the encoding happens on your own machine, which keeps private recordings private and removes the upload wait entirely.
Frequently asked questions
Why do so many apps reject WebM?
WebM was designed for web browsers, so desktop editors, some phones and several social platforms never added support for it. MP4 with H.264 is the safe common denominator they all accept.
Where do WebM files usually come from?
Screen-recording extensions, browser-based recorders and some game capture tools save WebM by default. Those files play fine in Chrome but often fail everywhere else until converted.
Will my WebM lose quality as MP4?
The output is encoded to H.264, a lossy codec, so expect a small change. WebM sources are usually already compressed, and re-encoding at a generous resolution keeps the result visually close.
Does the audio survive the conversion?
Yes, the audio track is encoded to AAC in the MP4. Subtitle tracks stored inside the WebM are not copied, so keep the original file if you rely on them.
Is anything uploaded while converting?
No. The converter runs in your browser tab. The WebM file is read locally, encoded locally and downloaded straight back to your device.
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