How to Convert WebM to MP4 Online
Follow these three simple steps to convert WebM to MP4. No software installation required. Free and secure.
Select a WebM Video
Choose a WebM video from a website, browser recording, web application, or another source on your device.
Choose Video and Audio Settings
Keep the original resolution and frame rate or choose new values, then keep the automatic audio settings or select a sample rate and mono or stereo output.
Convert and Download
Start the conversion, review the original and output file sizes, and download the completed MP4 video.
How Does the WebM to MP4 Converter Work?
The CompressFly WebM to MP4 converter decodes supported WebM video and audio, re-encodes the picture as H.264 and available audio as AAC, and places the result in an MP4 container. The new file targets broader device and application support than the WebM source.
Conversion runs directly in your browser. Your WebM video is not uploaded to a server, and the completed MP4 file downloads from the browser to your device.
What "directly in your browser" means
- Your WebM video is not uploaded to a server.
- Video conversion runs locally on your device.
- The completed MP4 video downloads directly from your browser.
When to Convert WebM to MP4
Create an MP4 copy when a WebM video must work in an editor, social platform, device, or delivery workflow with limited WebM support.
Open WebM in More Applications
Convert browser-oriented WebM video for an editor, presentation tool, or media player that expects MP4.
Upload to Social Platforms
Prepare a WebM clip for a social network, messaging service, or upload form that does not accept the source format.
Create a General Delivery Copy
Make an H.264 MP4 version for recipients and devices while retaining the original WebM for its web workflow.
Related Video Tools
WebM to MP4 Converter FAQ
How do I convert WebM to MP4 online?
Use this online WebM to MP4 converter in three steps: 1. Select a WebM video from your device. 2. Keep or change the available video and audio settings. 3. Start the conversion and download the completed MP4 video.
What happens when I convert WebM to MP4?
Supported WebM video and audio are decoded, then re-encoded as H.264 video and AAC audio inside a new MP4 file.
Why convert WebM to MP4?
WebM works well in web environments, but some editors, social platforms, and devices prefer MP4. Converting creates a separate compatibility copy without changing the source WebM.
Can I change the video resolution and frame rate?
Yes. Keep the source resolution and frame rate or select an available output resolution and frame rate before conversion.
Will converting WebM to MP4 make the file smaller?
Not necessarily. The output size depends on the source video, selected resolution, frame rate, audio settings, duration, and visual content. Use the Video Compressor when reducing file size is the main goal.
Is the WebM to MP4 converter free?
Yes. Convert WebM to MP4 for free with no registration or credit card required.
Is there a file size limit, and is my video uploaded?
Your video is processed locally in your browser and is not uploaded to a server, so there is no server upload limit. The practical limit depends on your device's available memory and processing power, as well as the video's duration and resolution.