Ultraconvert
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100% client-side — your videos never leave your device

Video & MP3 converter,
without the upload.

Convert MP4 and WebM, extract MP3 audio, resize, change bitrate and framerate — right in your browser. Drag, drop, done.

How it works

  1. 1

    Drop your video

    Add an MP4 or WebM file. It's decoded locally with WebCodecs — no upload.

  2. 2

    Set output

    Convert to MP4 or WebM, or extract MP3 audio. Adjust resolution, bitrate and framerate.

  3. 3

    Download

    Save the converted video or audio. Nothing is ever sent to a server.

Frequently asked questions

Are my videos uploaded to a server?+

No. Video is decoded and encoded in your browser via the WebCodecs API and mediabunny. Your files never leave your device.

Can I extract MP3 audio from a video?+

Yes. Drop an MP4 or WebM and export just the audio track as an MP3.

What can I change during conversion?+

Output format (MP4 / WebM / MP3), resolution, bitrate and framerate.

Is it free?+

Yes — free, no signup, no watermarks.