Filenary

MP4 to M4A Converter

Convert MPEG-4 video files to M4A audio right in your browser — free, private and with no size limit.

Drop your file here

or click to browse

Choose File

On first use, a ~30 MB conversion engine is downloaded to your browser (one time only).

This file is processed in your browser and never uploaded to a server.

How to convert MP4 to M4A

  1. 1Drop your MP4 file into the box above, or click to choose it from your device.
  2. 2Click Convert. The conversion runs locally in your browser — nothing is uploaded.
  3. 3Download your new M4A file as soon as it's ready.

Why convert MP4 to M4A?

MP4 files can be larger than newer formats like WebM at the same quality. M4A is the native audio format for iPhone, iTunes and Apple Music.

Why people make this conversion

The audio track with full iTunes and iPhone compatibility in one click.

The size math: MP4 vs M4A

A minute of MP4 video weighs about 9 MB; its soundtrack alone as M4A is 1.9 MB. Extracting audio shrinks the file about 4.7× smaller.

What is MP4?

MP4 is the most compatible video format, using H.264 video and AAC audio. It plays on every phone, browser, TV and social network.

  • MIME type: video/mp4
  • Standardized: 2001 (MPEG-4 Part 14)
  • Usual codecs: H.264 or H.265 video plus AAC audio
  • The universal container: phones, TVs and editors all accept it

What is M4A?

M4A is an audio file in an MPEG-4 container, usually AAC. It's the default audio format on iPhone and in iTunes.

  • MIME type: audio/mp4
  • Introduced: 2003 with the iTunes Store
  • An MP4 container holding AAC (rarely ALAC) audio
  • Same sound as a bare .aac file, with wider app support

Frequently asked questions

Is this MP4 to M4A converter free?
Yes, it's completely free with no sign-up, no watermark and no daily limits.
Are my MP4 files uploaded to a server?
No. The conversion happens entirely inside your browser, so your files never leave your device.
Is there a file size limit?
Filenary sets no limit — even files over 1 GB work. The only practical limit is your device's memory.
Will converting MP4 to M4A reduce the quality?
M4A uses lossy compression, so the file becomes smaller with a small, usually invisible, loss of detail. Settings are tuned to keep the result sharp.
Can I convert several MP4 files at once?
This converter handles one file at a time. When it's done, click Start over to convert the next MP4 file.
Does it work on iPhone, Android, Mac and Windows?
Yes. It runs in any modern browser — Chrome, Safari, Edge or Firefox — on phones, tablets and computers, with nothing to install.

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Add this tool to your website

Copy the code below and paste it into any page. It's free, needs no sign-up, and files are processed in your visitors' own browsers.