MP4 to MP3 converter

Extract MP3 audio from MP4, MOV, and WebM videos in your browser.

Runs on your deviceFreeNo account

How to use MP4 to MP3

Drop an MP4, MOV, MKV, or WebM. Allow the FFmpeg engine to load on first use. Omnipus strips the video track and encodes MP3. Download the audio. Only convert files you own or have rights to process.

Add your file

Drag & drop, browse files, or press Ctrl+V to paste from the clipboard where supported.

Process in the browser

Work stays in this tab with WebAssembly, Canvas, or other on-device APIs — your file is not uploaded to Omnipus.

Download or share

Save the result to your device, or share it with the OS share sheet when available.

Direct share: Install Omnipus as an app on Android to share files and links into this tool from other apps.

About this tool

Extract audio from video lectures, interviews, and clips with FFmpeg running as WebAssembly in your browser. The first conversion downloads the encoder (then caches it); the media itself is not uploaded to Omnipus.

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Frequently Asked Questions

Why is the first run slow?

The FFmpeg wasm build downloads once, then is cached by the browser.

Is video uploaded?

No. Decoding and encoding happen locally.

Other audio formats?

MP3 is the default for wide compatibility; see related audio tools for WAV.

Long videos?

Phone browsers may struggle with hour-long 4K files — trim first when possible.

Is MP4 to MP3 completely free to use?

Yes. MP4 to MP3 on Omnipus is free to use with no subscription paywall for the tool itself.

Are my files or data uploaded to any servers?

No. MP4 to MP3 processes your input locally in this browser tab. Your files and text are not sent to Omnipus. Some tools download an engine or model file the first time you use them; that is a download, not an upload.

Does Omnipus add watermarks to exported files?

No. Omnipus does not stamp a site watermark onto files you export from MP4 to MP3.

Can I use MP4 to MP3 on my mobile phone?

Yes. Omnipus has touch-friendly controls and can be installed as an app. On Android you can also share files or links into tools from other apps.

Related tools

More video & audio that pair well with this one.

Video to GIFTurn a short video clip into an animated GIF.Text to speechListen to any text with your browser’s built-in voices.WAV to MP3Compress a WAV recording into an MP3.MP3 to WAVDecode an MP3 to uncompressed WAV.Video trimmerCut a clip by start time and duration in the browser.MP4 to WebMConvert an MP4 to WebM for the web.