MP4 to AAC Converter
Pull the audio track out of a MP4 file and save it as AAC — no upload, done entirely on your device. Drop a MP4 file below to get started.
Drop files, or click to browse
MP4 files only — processed one at a time
Frequently asked questions
Is this MP4 to AAC converter free?+
Yes, with no watermark, no account, and no daily limit.
Is my audio file uploaded anywhere?+
No — conversion runs locally using your browser's own built-in media codecs, entirely inside your browser tab.
Will this keep the video too?+
No — this tool extracts just the audio track and discards the video, giving you a standalone audio file.
Is there a maximum file size?+
There's no fixed file-size limit since nothing is uploaded to a server. Processing time scales with the track's length rather than a hard cutoff.
How do I convert MP4 to AAC?+
Drop your MP4 file into the box above — it's decoded and re-encoded as AAC automatically, with a download ready in seconds.
About MP4 and AAC
What is MP4?
MP4 (usually carrying H.264 video) is the most widely compatible video container — it plays on essentially every phone, browser, and TV.
Full MP4 format guide →What is AAC?
AAC is the compressed audio format behind iTunes, YouTube, and most streaming services — generally more efficient than MP3 at the same bitrate.
Full AAC format guide →The short version: AAC gives you better quality-per-kilobit than MP3, which helps once you run into MP4's biggest limitation: not the smallest option available for the same visual quality. It's a natural move when your video is headed toward music and podcasts on Apple devices.
How it works
- 1
Drop your file in
Drag your audio onto the box above, or click it to browse — there's no account to create and no upload to wait on.
- 2
Pick your settings
The output format is already set for this page — just adjust any extra options shown, if there are any.
- 3
Download the result
Your browser processes everything locally and hands you a download link the moment it's done — nothing was ever sent to a server.
Is it private?
Everything happens locally, inside this browser tab. Your audio is read from disk, processed with WebAssembly running on your own device, and handed back to you as a download — it's never transmitted anywhere, so there's nothing to intercept and nothing stored on a server.
Common use cases
- Music and podcasts on Apple devices
- Streaming
- Prepping a podcast episode for a hosting platform
- Fitting a voice memo under a messaging app's size limit
Supported formats
This is one of many pairings the audio toolkit handles. In total it covers:
Related conversions
Format details
About MP4 files+
MP4 (usually carrying H.264 video) is the most widely compatible video container — it plays on essentially every phone, browser, and TV.
MP4 is a container format standardized under MPEG-4, meaning the file itself is really a wrapper that most often holds H.264-encoded video alongside AAC audio. That specific combination struck a balance efficient enough for streaming and broad enough to be adopted everywhere, which is why it's the format cameras, phones, editors, and social platforms converge on as a safe default. It isn't always the smallest or most efficient option available — newer codecs inside newer containers can do better — but nothing beats it for guaranteed playback.
How to open a MP4 file
Opens readily in Any web browser, Any modern phone, TV, or media player. For real editing, use Adobe Premiere Pro, DaVinci Resolve, iMovie.
Good for
- maximum device and platform compatibility
- good compression-to-quality ratio
Watch out for
- not the smallest option available for the same visual quality
About AAC files+
AAC is the compressed audio format behind iTunes, YouTube, and most streaming services — generally more efficient than MP3 at the same bitrate.
AAC (Advanced Audio Coding) was developed as the designated successor to MP3 under the MPEG standard, using newer compression techniques to squeeze out noticeably better sound quality at the same bitrate, or an equivalent quality at a smaller file size. Apple adopted it as the default format across iTunes and the iPhone early on, and it's since become the standard codec behind most video and streaming platforms as well, since it handles the low bitrates needed for streaming particularly well.
How to open a AAC file
Opens readily in Any modern media player, Any web browser, iTunes/Apple Music. For real editing, use Audacity (free), Adobe Audition.
Good for
- better quality-per-kilobit than MP3
- the default format across Apple's ecosystem
Watch out for
- slightly less universal hardware support than MP3, though still very broad
Need a different format? Try the full Audio Converter, or explore all audio tools.