PRIVATE BROWSER PROCESSING
Convert WebM to MP4 when compatibility matters more
WebM is a sensible web format, but MP4 still fits more upload forms, editing apps and everyday devices. Re-encode your WebM into a broadly usable MP4 without uploading it.
WebM to MP4
WebM is web-friendly; MP4 is still the safer hand-off format
The conversion uses H.264 video and AAC audio for the MP4 result. Re-encoding takes longer than a simple container change, but avoids relying on whether the original WebM codecs fit MP4.
Privacy and limitations
Processing uses FFmpeg WebAssembly locally. The video is not uploaded by this tool. Closing or refreshing the page clears the working file. Speed depends on the browser, device memory, source codec, duration, and resolution, and tools that re-encode are not lossless.
Common questions
Can I just rename the file extension?
Usually not. Renaming does not change the container or codecs inside; this page performs a real conversion.
Is my video uploaded to DJAI?
No. The source file is read and processed in your browser on your device.
Why can the first run take longer?
The browser downloads an FFmpeg WebAssembly core of roughly 31 MB the first time processing is needed; caching can help later runs.