MediaCC private browser tool
MP4 to WebM Converter
Convert MP4 to WebM with MediaCC directly in your browser. Your media files stay on your device and are not uploaded to MediaCC servers.
How to convert MP4 to WebM
- Open the MediaCC video converter.
- Select your MP4 file from your device.
- Choose WebM as the target format and start conversion.
- Download the converted WebM file when local processing finishes.
Browser-based conversion notes
MediaCC processes files locally in supported browsers. Image output is focused on JPG, PNG, and WebP; HEIC/HEIF photos can be converted to JPG, PNG, or WebP. Video conversion uses FFmpeg.wasm and works best with common formats such as MP4, MOV, WebM, MKV, and AVI.
File limits
You can process up to 15 files per session, with a 150MB single-file limit and 1000MB total session limit. Large videos may take several minutes depending on file size, duration, format, and device performance.
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Frequently asked questions
Is MP4 to WebM conversion private?
Yes. MP4 to WebM conversion runs in your browser where supported, so your media file stays on your device.
Are my files uploaded to MediaCC servers?
No. MediaCC does not upload your selected media files to MediaCC servers for conversion. Processing happens locally in your browser where supported.
Is the MP4 to WebM converter free?
Yes. The MP4 to WebM converter is free to use, with no account required and no watermark added by MediaCC.
What file size limits apply?
You can process up to 15 files per session, with a 150MB single-file limit and 1000MB total session limit. Large videos may take several minutes depending on file size, duration, format, and device performance.
Why can video conversion take time?
You can process up to 15 files per session, with a 150MB single-file limit and 1000MB total session limit. Large videos may take several minutes depending on file size, duration, format, and device performance.