Convert WebM to MP4 Online
Convert WebM video to MP4 directly in your browser. Free, no signup, and your file is never uploaded.
Click to upload or drag a file here
Supported: WEBM · Processed entirely in your browser
Converted entirely in your browser using a WebAssembly build of FFmpeg — your file is never uploaded anywhere. Larger files take longer and use more memory.
WebM to MP4 converts a web-native video format into MP4, which is far more widely supported by phones, editing software and social platforms than WebM.
Why isn't WebM as universally supported as MP4, despite being a modern format?
WebM was designed specifically for efficient browser streaming, not for broad compatibility with editing software, phones and social platforms — many of those tools were built assuming MP4 as the default, so a WebM file, even though technically capable, can hit compatibility gaps that converting to MP4 sidesteps entirely.
Does converting from WebM to MP4 change the video quality?
It depends on how the conversion is handled — a straightforward container conversion keeps quality close to the original, though re-encoding between different underlying video codecs (VP8/VP9 in WebM versus H.264 or similar in MP4) can introduce a small amount of quality change either way.
Is this private, and does the video get uploaded anywhere?
No — conversion happens entirely in your browser, so the video is never uploaded to a server; it's also free, with no sign-up and no limit on how many files you convert.
Why do two competing 'free' video formats even exist for the same job?
Because the video codec commonly used inside MP4 files, H.264, wasn't actually free — companies distributing H.264 video or building H.264 encoders/decoders have historically owed licensing royalties to a patent pool, a real cost for browser makers and websites operating at huge scale. Google's answer, after acquiring codec company On2 Technologies for about $124.6 million in February 2010, was to open-source On2's VP8 codec and pair it with an open container format to create WebM — a video format any website or browser could use completely free, announced at Google I/O that May. MP4 remained the safer universal choice because of its sheer install base and hardware support built up over its own longer history, but WebM's entire reason for existing was to give the web an alternative that didn't come with a licensing bill attached.
Is WEBM to MP4 free to use?
Yes. WEBM to MP4 is completely free, with no sign-up and no usage limits.
Do I need to install any software?
No. WEBM to MP4 runs directly in your web browser — nothing to download or install.
Is my data kept private?
Everything happens on your device. We never receive or store the file or text you enter into WEBM to MP4.