Convert MP4 to WebM Online
Free, private MP4 to WebM converter. Your files never leave your browser. All processing happens locally on your device.
Drag & drop files here
images, PDFs, documents, audio, video, and more
No Server Uploads
FormatShift converts files directly in your browser. Your files never leave your device, so there's nothing to intercept or leak.
Instant Export
Files convert on your machine, so downloads are ready right away, even on slow connections.
High Fidelity
Good encoding keeps your files looking and sounding right, even at smaller sizes.
Built for Privacy
Your files are processed entirely in your browser. They never leave your device.
How to convert MP4 to WebM
Drop your MP4 file
Drag your file onto the converter above, or click to browse your files. Your files stay on your device.
Automatic conversion
FormatShift converts your file right in your browser using WebAssembly. No server involved, so your data stays completely private.
Download your WebM file
Once the conversion finishes, click the download button and you are done. The converted file is ready to use.
Why convert MP4 to WebM?
WebM is the preferred format for embedding video on web pages. If you are building a website and want to use HTML5 video, converting your MP4 to WebM gives you a royalty-free option that works well in all browsers.
What is a MP4 file?
MPEG-4 Part 14: MP4 is the most widely used video format. Phone recordings, YouTube downloads, streaming services, social media, almost everything uses MP4. It supports video, audio, and subtitles in a single file.
Created by: Moving Picture Experts Group (ISO/IEC), standardized in 2001
Used for: Video streaming, social media, phone recordings, web video, TV shows and movies
Technical details: Container format supporting H.264/H.265 video, AAC audio, and subtitle tracks. Lossy compression provides good quality at manageable file sizes.
Compatibility: Plays on virtually every device, browser, and operating system without extra software.
What is a WebM file?
WebM Video: WebM is Google's open video format designed for the web. It tends to produce smaller files than MP4 while keeping comparable quality, though compatibility outside of web browsers is more limited.
Created by: Google, first released in 2010
Used for: Web video, HTML5 video elements, web applications
Technical details: Container format using VP8/VP9 video and Vorbis/Opus audio. Open and royalty-free. Good compression efficiency.
Compatibility: Supported by all major browsers (Chrome, Firefox, Edge, Safari). Desktop media players like VLC handle it. Some mobile apps and editors may not.
MP4 vs WebM
| Feature | MP4 | WebM |
|---|---|---|
| Type | MPEG-4 Part 14 | WebM Video |
| Best for | Video streaming, social media, phone recordings, web video, TV shows and movies | Web video, HTML5 video elements, web applications |
| Compatibility | Plays on virtually every device, browser, and operating system without extra software. | Supported by all major browsers (Chrome, Firefox, Edge, Safari). Desktop media players like VLC handle it. Some mobile apps and editors may not. |
| Pros | Universal compatibility, good compression, supports multiple streams | Smaller files than MP4, open and royalty-free, excellent browser support |
| Cons | Lossy compression means some quality loss, editing requires re-encoding | Less compatible than MP4 outside of browsers, limited editing tool support |