WebM to MP4 Converter – Free Online

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How to Convert WebM to MP4 Online

Upload your WebM file

Drag and drop your .webm file onto the page or click to browse. You can select several WebM files at once to batch-convert them.

MP4 is preselected

The output format is already set to MP4, so you can convert immediately. If you need to, adjust the codec, resolution, frame rate or bitrate in the settings panel first.

Convert and download

Click Convert. The MP4 file is processed on your own device; nothing is uploaded to a server. When it finishes, click Download to save it (or Download all to get a batch as a ZIP).

Why Convert WebM to MP4?

WebM is great inside Chrome but Safari, iOS, PowerPoint, Premiere Pro and most TVs will not open it. Converting WebM to MP4 re-encodes the VP8 or VP9 video to H.264 and the Opus audio to AAC, giving you a file that plays and edits anywhere.

Screen recordings from Chrome extensions, Loom and Google Meet are the most common WebM sources. Drop the file in, keep the resolution, and the converter produces a standard MP4 on your own machine with no upload and no waiting in a queue.

Private by design: your WebM file is converted on your own device and never uploaded.
MP4 preselected: the output format is already chosen, so it is a one-click conversion.
Batch friendly: convert several WebM files in one go and download them as a ZIP.
No limits, no watermark: free for files of any size, with nothing stamped on the output.

WebM vs MP4

WebM (WebM): WebM is the open, royalty-free container built for the web. It pairs VP8, VP9 or AV1 video with Opus or Vorbis audio and streams natively in Chrome, Firefox, Edge and HTML5 players. It is best for HTML5 video, websites and open-source projects.

MP4 (MPEG-4 Part 14): MP4 is the most widely supported video container in the world. It usually carries H.264 or H.265 video with AAC audio, plays on every phone, browser, TV and editing app, and is the safest choice for sharing. It is best for sharing, social media, web playback and mobile devices.

In short: keep WebM when the priority is HTML5 video, websites and open-source projects, and switch to MP4 when the file is headed for sharing, social media, web playback and mobile devices. Need a different target? The full Video Converter supports every format listed below.

WebM to MP4 FAQ

Why is WebM to MP4 slower than other conversions?

WebM video must be fully re-encoded from VP8/VP9 to H.264, which is CPU-intensive. Long recordings take a few minutes; the page shows live progress.

Can I convert a WebM file that has no duration?

Yes. Browser screen recorders often omit the duration header. The converter scans the whole file, so the MP4 gets a correct length and seek bar.

Is this WebM to MP4 converter free?

Yes. Converting WebM to MP4 on MediaConverter.io is completely free, with no watermark, no sign-up and no daily conversion limit.

Are my WebM files uploaded to a server?

No. The converter runs inside your browser using WebAssembly and WebCodecs, so your .webm file is read and converted on your own device. Nothing is uploaded, which keeps private recordings private and means there is no waiting in an upload queue.

Is there a file size limit for WebM to MP4?

No fixed limit. Because processing happens locally, the practical limit is your computer's memory and patience; multi-gigabyte WebM files convert fine on a desktop browser. Very large files take longer on phones.

Will converting WebM to MP4 reduce quality?

The video is re-encoded into MP4. Keep the source codec, resolution and bitrate (the defaults) and the result is visually the same as your WebM; lowering the bitrate or resolution is what reduces quality, and you control that trade-off in the settings panel.

Which browsers support the WebM to MP4 converter?

Current versions of Chrome, Edge, Firefox and Safari on desktop all work. Chrome and Edge are fastest because they expose hardware-accelerated WebCodecs decoders.