How to use it
- Choose or drop a WEBM file.
- Choose the output format, codec and available bitrate settings.
- Convert, review the result, then download your file.
When to convert WEBM to MP4
WebM recordings often use VP8 or VP9 video and Opus audio. Keeping those codecs in MP4 may limit playback in other applications. Choose H.264 and AAC when your destination requires them.
MP4 is useful for social uploads and sharing. H.264 video with AAC audio is a common compatibility choice. An MP4 extension alone does not guarantee that a service accepts the codecs, dimensions or bitrate inside it.
Common questions
Is it free without an account?
Yes. There is no signup, watermark, or charge to download. Your browser does the processing.
Which tracks are kept?
The primary video and audio tracks are used, except when you choose Remove audio. Extra tracks, subtitles and attachments are omitted. Unsupported selected tracks produce an error instead of silently disappearing.
Why is a codec missing or a conversion blocked?
Codec support depends on your browser, operating system, device and source profile. The menus list available output encoders, and conversion checks the actual source. Try a current Chrome or Edge browser, another format, or Keep source codec for a compatible container.
Does conversion always preserve quality?
Keeping compatible encoded tracks avoids recompressing them. Re-encoding with a lossy codec can reduce quality. Lossless output preserves decoded samples but cannot recover detail lost in an earlier encoding.