AAC vs. MP3: Which Audio Format to Choose?

Wondering which format will better suit your needs? Check the differences!

  • MP3 overview
  • AAC overview
  • The main differences
  • Converting files

Edited by Ben Jacklin

January 15, 2020

AAC vs. MP3: Which Audio Format is the Best for Your Music?

When thinking about audio quality, the debate of AAC vs. MP3 file formats comes to mind. Will you opt for MP3 or AAC as you download that hit song? Does the size of the audio files matter? Do they play on all devices?

Answers to such questions can clear your mind on the MP3 vs. AAC debate. For a start, it is essential to note that these two file types provide almost similar audio quality. Encoding speed and device speakers have a more significant influence on audio quality.

So, why should you care about the MP3 vs. AAC discussion? From file size to sound quality and music device, these two file formats will influence your audio experience. Read on to find out whether AAC or MP3 will serve your needs best.

You can also check out Movavi Video Converter – a simple and effective tool for switching between video, audio, and image formats.

MP3 vs. AAC

MPEG-1 Audio Layer3 (MP3) has been the standard format for music playback on different digital audio players. The Advanced Audio Coding (AAC) format, on the other hand, looks to become the successor of the MP3 format. Both these audio-specific formats are flossy formats meaning that they use compression to create smaller audio files. The 128 kbps setting, for example, will reduce the original file's size by 1/11. In the creation process, developers lose part of the original audio data. These flossy formats have allowed developers to package countless songs into scaled-down music players.

MP3 overview

The release of MP3 for public consumption took place in 1994, three years before the AAC format came to the market. Moving Pictures Experts Group (MPEG) adopted the MP3 format to be part of their MPEG-1 standard before later extending it to MPEG-2 standard.

MP3 has since become the most popular audio format, especially for storage and streaming purposes. Most audio players also use this format as the default playback and storage standard. MP3 files have the .mp3 file extension.

AAC overview

Developers of the AAC format intended to improve the compression scheme used for creating the MP3 file format. The idea was to create a format with better quality. Nokia, Dolby Laboratories, AT&T-Bell Laboratories, and Sony Corporation all had a hand in the development of this file format.

MPEG adopted this format as part of both its MPEG-2 and MPEG-4 standards. New audio devices and media players support the AAC format which doubles as the default audio format for iPhone, iTunes, iPad, PlayStation 3, YouTube as well as iPod. The AAC format files have a host of file extensions including, .m4a, .aac, .m4p, .m4r, .3gp, .m4b, .m4p, and .mp4.

MP3 versus AAC: The Differences

Let's now look at the properties that distinguish these two file formats, and try to find the better option.

Audio quality

While their sound capabilities don't vary considerably, AAC has the upper hand at lower bit rates. If you're working with bit rates lower than 128 kbps, you'll notice the difference. MP3 files will sound a little muddy and slurry while the AAC files maintain their brighter and clearer sound.

The AAC format leverages its optimal transform window sizes and pure MDCT to beat MP3 at these bit rates. While MP3 has sample frequencies ranging from 16 kHz to 48 kHz, AAC's sample frequencies range between 8 kHz to 96 kHz. With more sample frequencies, AAC developers can accurately reproduce the original files as they decrypt audio files.

With higher bit rates (192 kbps and above), the focus shifts from the audio format to the encoder. MP3 competes favorably and is surprisingly robust if you work with an efficient encoder. At high enough bit-rates, you'll hardly notice the difference between these formats and the original files.

File Size

When compressing audio files to create MP3 or AAC files, developers compromise quality for smaller audio files. You, therefore, end up with smaller audio files, although the AAC tends to be smaller than the MP3 format. With AAC files, developers can lower bit-rates reducing the files' size further than what MP3 files can achieve. The audio quality for AAC files remains intact in the process.


Developers have greater flexibility in the ACC format than MP3 when designing codecs. With this flexibility, you can simultaneously use multiple encoding strategies and compress your files more efficiently.

MP3 files can only store two channels of synchronous audio compared to AAC's 48 channels. This specification lets you compress multichannel audio on AAC with less hassle. You'll also have an easier time working with surround sound mixes.

With a pure MDCT, AAC boasts of higher encoding efficiency. The MP3 format, on the other hand, uses a hybrid coding system that comprises the overall encoding process. MP3's block size of 576 samples further reduces the coding efficiency. AAC uses 940 or 1024 samples, further enhancing the encoding.

When it comes to the accuracy of transient signals, AAC has the upper hand with the 128 samples block size compared to MP3's 192 sample size.

Do you want to correct the design choices on original MP3 files? The AAC format lets you create audio files with your preferred specifications. As you use your encoder, watch out for the encoding speed which ultimately influences how your track sounds. Some AAC encoders may not leverage all of AAC's additional encoding tools. There is little wonder, therefore, that you won't notice the subtle differences between the MP3 and AAC audio files.

Licensing and Patents

Are you looking to distribute your audio files? With no payment or license requirements, AAC is the right choice on this end. This format is also better for streaming content. The only patent requirements come into play when you choose to create AAC codecs.

For the MP3 format, some companies like Audio MPEG and Texas MP3 Technologies claim control over the patents. These patents do not, however, hold water in some countries. Such licensing and patenting issues have done little to lower the popularity of this file format.

Supported Devices

MP3 files can play in pretty much any device and operating system, giving it more popularity than AAC files. iTunes and Apple Music users, however, prefer the AAC files. The AAC format may not necessarily play on every device, especially the Android and Windows devices. This subdued support for AAC files is since it is newer. On availability, Amazon MP3 is an excellent store for top quality MP3 files. For AAC files, you'll find your favorite songs in the Apple iTunes.

The Verdict

Now to the big question. Is AAC better than MP3? On matters quality, AAC dominates MP3 at lower bit-rates. However, at normal bit-rates (above 160 kbps), the differences are hardly noticeable. While regular listeners won't mind listening to MP3 files, audiophiles generally prefer AAC file formats. Ultimately, the choice between the two formats is subjective.

However, to help you make the right choice here is a comparison table.

Sound QualitySound quality is better than MP3 on lower bitratesLower than AAC at the low bitrate. Almost the same quality at higher bitrate
File SizeSmallLarge
CompatibilityMostly Apple devices, since the format is newerAlmost any device and OS

If you want to convert lossless audio files to other formats, you can choose to either save your files as AAC or MP3. Which one of the two is better? If you are considering compatibility, then the MP3 is a better option. For smaller audio files with better quality, opt for the AAC file format.

If you love listening to music on Android, the MP3 file format should work just fine. iPhone users, on the other hand, will be better placed going for AAC files. Do you need a program to convert media files? Try Movavi Video Converter and enjoy your listening experience.

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