How does the MP4 to AAC converter work?

Upload your MP4 files and start the conversion. FFmpeg takes the default audio track and writes it as a .aac audio file, leaving the picture out.

Can I use the converter without signing up?

Yes. You can upload, convert and download without an account. Free use has a daily limit, and a $2.99 or $6.99 pass removes it, with no monthly subscription.

Are there file-size limits?

Each MP4 file can be up to 20GB.

Does this work in a mobile browser?

Yes. dragdropdo runs in Safari, Chrome and other mobile browsers on iPhone, iPad and Android, so you can convert MP4 files on a phone or tablet without installing an app.

Can I batch convert MP4 files?

Yes. Add several MP4 files to one job, then download each AAC file on its own or all of them together as a ZIP.

Is the audio re-encoded?

Not when the MP4 carries AAC-LC, HE-AAC or HE-AACv2, which covers nearly every MP4. Those frames are copied bit for bit, so the bitrate, channels and sample rate stay the same, including 5.1. Other audio, including MP3, AC-3, E-AC-3, ALAC, Opus, PCM and AAC-ELD or AAC-LD, is converted to AAC-LC at 192 kbps for stereo or 128 kbps for mono, with more than 2 channels mixed down to stereo and sample rates kept up to 48 kHz. Copied HE-AAC is signaled implicitly, so players without HE-AAC support play only its basic AAC-LC layer, which sounds duller.

Which audio track is extracted?

One track: the default (enabled) track, otherwise the first. Other language or alternate tracks are not included.

Does the .aac file keep tags, chapters or cover art?

No. A raw .aac (ADTS) file has no place for tags, chapters, cover art or a seek index. If you want title and artist tags or chapters, convert MP4 to M4A instead, which keeps the same AAC audio in a tagged file.

Why does my player show a slightly different length?

ADTS has no length field, so players estimate the duration from the stream, and seeking can be slow. A copied stream also keeps the encoder's start-up silence of about 20-50 ms, so the reported length is about 0.1 s longer than the sound itself.

Will the AAC file stay in sync with the video?

Only when the sound starts with the picture. If the video's sound starts late or has dropouts, the .aac contains only the sound itself, without the silence. To keep the audio in sync with the video, convert MP4 to M4A or WAV instead, which fill the gaps with silence.

Which MP4 files can't be converted?

DRM-protected MP4s fail with a clear message. That covers CENC-encrypted streaming and DASH downloads and FairPlay-protected videos. MP4s with no audio track or an empty one, damaged or unreadable files and audio that can't be decoded also stop with a message.

How does the MP4 to AAC converter work?

Upload your MP4 files and start the conversion. FFmpeg takes the default audio track and writes it as a .aac audio file, leaving the picture out.

Can I use the converter without signing up?

Yes. You can upload, convert and download without an account. Free use has a daily limit, and a $2.99 or $6.99 pass removes it, with no monthly subscription.

Are there file-size limits?

Each MP4 file can be up to 20GB.

Does this work in a mobile browser?

Yes. dragdropdo runs in Safari, Chrome and other mobile browsers on iPhone, iPad and Android, so you can convert MP4 files on a phone or tablet without installing an app.

Can I batch convert MP4 files?

Yes. Add several MP4 files to one job, then download each AAC file on its own or all of them together as a ZIP.

Is the audio re-encoded?

Not when the MP4 carries AAC-LC, HE-AAC or HE-AACv2, which covers nearly every MP4. Those frames are copied bit for bit, so the bitrate, channels and sample rate stay the same, including 5.1. Other audio, including MP3, AC-3, E-AC-3, ALAC, Opus, PCM and AAC-ELD or AAC-LD, is converted to AAC-LC at 192 kbps for stereo or 128 kbps for mono, with more than 2 channels mixed down to stereo and sample rates kept up to 48 kHz. Copied HE-AAC is signaled implicitly, so players without HE-AAC support play only its basic AAC-LC layer, which sounds duller.

Which audio track is extracted?

One track: the default (enabled) track, otherwise the first. Other language or alternate tracks are not included.

Does the .aac file keep tags, chapters or cover art?

No. A raw .aac (ADTS) file has no place for tags, chapters, cover art or a seek index. If you want title and artist tags or chapters, convert MP4 to M4A instead, which keeps the same AAC audio in a tagged file.

Why does my player show a slightly different length?

ADTS has no length field, so players estimate the duration from the stream, and seeking can be slow. A copied stream also keeps the encoder's start-up silence of about 20-50 ms, so the reported length is about 0.1 s longer than the sound itself.

Will the AAC file stay in sync with the video?

Only when the sound starts with the picture. If the video's sound starts late or has dropouts, the .aac contains only the sound itself, without the silence. To keep the audio in sync with the video, convert MP4 to M4A or WAV instead, which fill the gaps with silence.

Which MP4 files can't be converted?

DRM-protected MP4s fail with a clear message. That covers CENC-encrypted streaming and DASH downloads and FairPlay-protected videos. MP4s with no audio track or an empty one, damaged or unreadable files and audio that can't be decoded also stop with a message.

Free MP4 to AAC Converter Online

Convert MP4 to AAC online and extract the sound from phone, camera and screen recordings. Upload files up to 20GB and download the converted result in a few clicks.

Drag & Drop your MP4 file here

MP4 files, up to 20GB

Files stay private.

Automatically deleted after 24 hours.

Link 20GB upload limit.

4.8/5

Trusted for 1,827,796+ conversions

HOW IT WORKS

Convert MP4 to AAC in three steps

Three steps, no account, nothing to install.

Add your MP4 files

Drag and drop or upload the MP4 videos whose sound you want as an AAC file.

Copy or encode the AAC stream

AAC-LC and HE-AAC audio is copied as it is. Other audio, such as MP3, AC-3 or Opus, is encoded to AAC-LC.

Download the AAC

Save each AAC file as it finishes, or download several together as a ZIP.

MP4

MP4 (MPEG-4 Part 14) is the most widely supported video container, used by phones, cameras, screen recorders, social platforms and video downloads. The sound inside an MP4 is usually AAC.

AAC

AAC (Advanced Audio Coding) is the lossy codec inside most MP4 videos and M4A songs. A .aac file holds that stream on its own in ADTS framing, without a container, so it has no tags, chapters or cover art. VLC and most desktop and mobile media players open it.

FILE FORMATS

MP4 and AAC compared

SOURCE

MP4

MPEG-4 Part 14 is the default container for phone recordings, web video and streaming. MP4 with H.264 video and AAC sound plays on iPhone and Android, in every browser, on smart TVs and in Windows and Mac players without extra codecs. It holds text subtitles and chapters, but not picture-based subtitles.

TARGET

AAC

Advanced Audio Coding replaced MP3 as the standard for phones and streaming: YouTube, Apple Music and Android all use it. It sounds better than MP3 at the same bitrate. A .aac file is a raw ADTS stream with no container, so it can't carry album art or chapters and some apps show limited tag information.

Feature	MP4	AAC
Developed by	MPEG (ISO)	MPEG (ISO)
File extension	.mp4	.aac
Holds	Video and sound	Sound only
Compression	Lossy (codec inside)	Lossy
Best for	Sharing and playback anywhere	Efficient compressed audio
Opens in	Yes	Yes, most devices

USE CASES

Use Cases for MP4 to AAC

Practical workflows where MP4 to AAC conversion is useful.

Keep the original AAC from a phone video

Pull the exact AAC stream out of a phone or camera MP4 without adding another round of compression.

Supply raw AAC to a broadcast or streaming tool

Some broadcast, streaming and hardware-encoder workflows expect a plain ADTS .aac file rather than an MP4.

Remux the sound into another video later

Keep the AAC stream on its own so it can be muxed into a new MP4, MKV or TS file later without re-encoding.

Play a soundtrack on a car stereo

Car stereos and portable players that list .aac among their supported files can play the soundtrack from a USB stick.

Archive lecture audio at its recorded quality

Keep the audio of a recorded lecture or meeting as a small .aac file at exactly the quality it was recorded in.

Save the music from a music video

Keep the AAC soundtrack of a music video or trailer without re-encoding and play it in a player that reads .aac files.

Send speech to a transcription service

Upload the extracted .aac to transcription or captioning tools that accept AAC instead of sending the whole video.

Get AAC from MP3, AC-3 or Opus audio

Videos whose sound is MP3, AC-3, E-AC-3 or Opus get an AAC-LC file at 192 kbps, with 5.1 mixed down to stereo, for devices that accept AAC.

Share a webinar's audio

Send the audio of a webinar or screen-recorded presentation as a compact .aac file instead of the full video.

Build a sound-effects library

Pull sounds from short MP4 clips, such as stock footage or your own field recordings, as AAC files for a sound library.

SUPPORTED FILES

Which MP4 Files Can I Convert?

MP4 videos from phones, cameras and downloads are supported.

Phone and camera videos

MP4s with AAC sound.

Screen and meeting recordings

Zoom, Teams and OBS MP4s.

Music videos you own

Keep the soundtrack as AAC.

Multi-track MP4

The default track is used.

A batch

Upload several MP4s and download the AAC files as a ZIP.

TROUBLESHOOTING

AAC Not Sounding Right?

Most issues come from which audio track the video contains.

The wrong audio track was used

Only the default track, otherwise the first, is extracted. Other languages and commentary aren't included.

There's silence at the start or in the middle

Gaps in the video's sound are filled with silence so the AAC stays in sync with the original timeline.

It says the video has no audio track

The video was recorded or exported without sound.

Album art and tags are missing

A raw .aac file has no place for cover art and few tags. Use MP4 to M4A for tagged files.

An app won't import .aac

Some apps only accept AAC inside .m4a. Try MP4 to M4A.

Still not working

Check the MP4 plays. A damaged file gives only the audio that can be decoded.

COMPARISON

dragdropdo vs. Desktop Video Tools

VLC, Audacity with its FFmpeg add-on and FFmpeg itself can pull sound out of a video once installed. dragdropdo is built for turning MP4 into AAC quickly, from any device.

What matters	dragdropdo	Desktop Video Tools
Nothing to install	✓Yes. Runs in any modern browser.	~Yes, a download. FFmpeg also needs the command line.
Works on phones and tablets	✓Yes. Desktop, Android, iPhone and iPad.	~Mostly desktop. VLC mobile can't export audio.
Batch conversion	✓Yes. Add many files and download one ZIP.	~FFmpeg can with scripts. VLC and Audacity do one file at a time.
Share finished files	✓Yes. Send a unique link from the result page.	~You upload and share the files yourself.
Pricing	✓Free with daily limits. $2.99 or $6.99 passes for unlimited use, no monthly plan.	~Free.
Picking which audio track	✓Uses the default track, otherwise the first.	~Yes. VLC and FFmpeg can export any track.

Other tools use different pricing, limits and workflows. This comparison describes dragdropdo's own features without assuming every other tool works the same way.

1.8M+

Files converted

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4.8

Average rating

from our users

~4s

Avg. conversion

per file

Files kept

Auto-delete in 24h

WHY DRAGDROPDO

Built to be quick, safe, and free

Convert MP4 to AAC in your browser, with nothing to install and nothing kept after 24 hours.

Private by default

Files are encrypted in transit and deleted from our servers automatically after 24 hours.

No install required

Convert in any modern browser on Windows, Mac, Linux, Android, iPhone or iPad. No app and no sign-up wall.

Big files and batches

Upload files up to 20GB each, add several at once, and download the results one by one or as a ZIP.

Share & download

Save finished files to your device or pass them on with a share link from the result page.

MORE MP4 TOOLS

Explore our other video operations

MP4, or MPEG-4 Part 14, is a digital multimedia format used to store video, audio, subtitles, and images. Its versatility and compatibility across devices make it a preferred choice for video streaming and file sharing. MP4 offers excellent compression for high-quality playback, making it ideal for online content, mobile use, and professional video editing. Optimize your digital media experience with the MP4 format.

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