VoxScriber

MP4 → M4A · Free · No Upload

Free Online MP4 to M4A Converter — No Installation

Convert MP4 (MPEG-4) to M4A (AAC) right in your browser, in seconds. Free, unlimited, and private: your file never leaves your device.

100% local processing: your file never leaves your device. Once the engine is ready, this tab can keep converting offline. Reopening or reloading offline may not work.

Supported formats:Files .mp4/.m4v up to 500 MB — processed locally · Video and virtually any audio format are also accepted — we extract the audio automatically.

How it works

  1. 01

    Upload the MP4 video

    Drag the .mp4/.m4v file to the area above or click to select. Files up to 500 MB are accepted — everything is processed locally.

  2. 02

    The conversion runs in your browser

    FFmpeg (the same engine used by professionals) runs in WebAssembly right on the page: the audio track is extracted from the video without sending any bytes to servers.

  3. 03

    Download the M4A

    In seconds, the .m4a file is ready for download, in 192 kbps AAC — high quality in a compact file.

Frequently asked questions

Why convert MP4 to M4A?

Many people only need the AUDIO from a video — to listen offline, edit in an audio app, or transcribe. Extracting MP3/WAV cuts the size by ~10× and unlocks the content. AAC delivers the same quality as MP3 with about 30% less space — it's MP3's technical successor and the Apple ecosystem standard.

Where do MP4 files come from?

Typically from phone cameras (Android and iPhone), recordings of classes, live streams, and meetings (Zoom, Meet, Teams) and course and video downloads. MP4 container with separate video and audio tracks; audio extraction doesn't re-render the video (fast and without extra loss).

Is it worth using M4A?

AAC delivers the same quality as MP3 with about 30% less space — it's MP3's technical successor and the Apple ecosystem standard. MP4 container (brand M4A); typical AAC-LC at 128–256 kbps. Note: an .m4a may contain ALAC (lossless) instead of AAC — same extension, different codecs.

Do I lose quality when converting MP4 to M4A?

There is a re-encoding between two compressed formats, with minimal technical loss — imperceptible for voice and most uses. If you're going to edit the audio multiple times, prefer converting to WAV or FLAC and compress only at the end.

What if I need a transcript of this audio?

After converting, you can transcribe the file with AI on VoxScriber: 30 free minutes per month, with automatic punctuation and speaker identification. Ideal for WhatsApp audio messages, meetings, and interviews.

Is my file sent to any server?

No. All processing is local (FFmpeg compiled to WebAssembly running on the page). The file never leaves your device—it even works offline after the page loads.

Is there a size or quantity limit?

The limit is 500 MB per file (browser memory). There is no limit on the number of uses. For larger files, VoxScriber processes them on the server with uploads up to 5 GB.

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