WEBM to MP4 Converter

Convert WEBM to MP4 privately using browser media codecs and no file uploads.

How to use

1. Convert WebM video to MP4 using browser-supported H.264 encoding.
2. Choose a file and convert it in this browser. Actual codec availability depends on your operating system and browser. Download and verify the resulting media.

About these formats

Container format and audio/video codec are different concepts. Transcoding may alter quality while transmuxing compatible media can preserve encoded data.

Browser limitations

Requires browser WebCodecs or bundled MP3 encoder. Hardware acceleration and supported codecs vary by browser. Maximum 120 MiB input, 400 MiB output. DRM and unsupported codecs cannot be converted; multi-track metadata may change.

Frequently asked questions

Are my videos uploaded?

No. Audio/video data stays inside your browser, and the encoder runs locally.

Does converting preserve quality?

Re-encoding lossy codecs may reduce quality. Keep the original file for archival use.

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