AAC vs. AC3 | Which Is Better in 2025?

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Edited by Ben Jacklin
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AAC vs. AC3: which one is better? When it comes to audio formats, particularly for video playback and streaming, AAC (Advanced Audio Codec) and AC3 (Dolby Digital) are two prominent codecs. Both formats are widely used for delivering high-quality audio, but they have more differences rather than similarities. Below, we explore the key differences and determine when each codec shines in the eternal AC3 vs. AAC battle.

Comparison parameter

AAC

AC3

Full name

Advanced Audio Codec

Audio Codec 3 (Dolby Digital)

Audio quality

Higher at lower bitrates

High, optimized for surround

Compression efficiency

More efficient

Less efficient

Bitrate range

8 Kbps to 320 Kbps

128 Kbps to 640 Kbps

File size

Smaller due to better compression

Larger compared to AAC

Compatibility

Universal across devices

Common in DVDs and cinemas

Surround sound support

Yes, up to 48 channels

Yes, up to 6 channels (5.1)

Usage

Streaming, music, mobile

Home theater, DVDs, Blu-ray

What is AAC?

AAC (Advanced Audio Codec) is a lossy audio compression format designed to replace MP3 as the superior standard for digital audio. It was developed by the MPEG group (Moving Picture Experts Group) and officially released in 1997. AAC offers excellent audio quality while maintaining smaller file sizes, making it perfect for modern streaming platforms like YouTube, Apple Music, and Spotify.

AAC supports up to 48 audio channels and boasts a wide bitrate range, from as low as 8 Kbps to 320 Kbps. This makes it ideal for everything from low-bandwidth streaming to high-fidelity audio playback. Its exceptional compression efficiency ensures that listeners get clearer, crisper sounds at lower bitrates compared to MP3 and AC3. The codec has become a standard for many devices, including mobile phones, streaming services, and online videos.

Key features of AAC:

  • High-quality audio at low bitrates
  • Better compression efficiency compared to older formats like MP3 and AC3
  • Widely supported across operating systems, streaming platforms, and hardware
  • Ideal for mobile devices, online streaming, and downloadable media

What is AC3?

AC3 (Audio Codec 3), commonly known as Dolby Digital, is a lossy audio codec developed by Dolby Laboratories in the early 1990s. It became a household name thanks to its widespread use in DVDs, Blu-ray discs, and home theater systems. AC3 is optimized for surround sound, supporting up to 6 channels (5.1) of audio, making it a go-to solution for cinematic experiences.

With a bitrate range of 128 Kbps to 640 Kbps, AC3 ensures high-quality audio reproduction for movies, TV shows, and video games. Although it offers impressive sound quality, particularly for surround setups, it is less efficient in compression compared to the AAC encoder. This often results in larger file sizes, which can be a drawback for streaming or mobile devices.

Key features of AC3:

  • Supports 5.1 surround sound for immersive audio experiences

  • Optimized for DVDs, Blu-rays, and home theater systems

  • Delivers robust sound quality at higher bitrates

  • Commonly used in cinema and digital TV broadcasts

AAC vs. AC3: Key differences explained

Deciding whether to pick AAC or AC3 can be tricky, as both codecs excel in different areas. To help you make an informed choice, let’s break down their key differences – from sound quality and file size to where they truly stand out in real-world applications:

Audio quality at low bitrates
AAC outperforms AC3 when it comes to audio quality at lower bitrates. While AC3 requires higher bitrates to maintain good audio fidelity, AAC can deliver clear and crisp sound even at reduced file sizes, making it the preferred choice for streaming and portable devices.

Compression efficiency
AAC is more advanced in terms of compression algorithms, resulting in smaller file sizes without compromising audio quality. In contrast, AC3's older technology leads to larger files, which can be less practical for mobile and online use.

Surround sound capabilities
AC3 supports 5.1 surround sound, which has long been the standard for home theaters. However, AAC offers far more flexibility, supporting up to 48 audio channels, making it ideal for more complex audio projects and multi-channel broadcasts.

Compatibility and usage
AAC enjoys broader compatibility across modern devices, streaming services, and operating systems, such as Windows, macOS, iOS, and Android. AC3, on the other hand, is primarily associated with DVDs, Blu-rays, and cinematic content, where its surround sound support shines.

Applications

  • AAC: best for streaming platforms, portable devices, music playback, and podcasts due to its efficiency and broad support.
  • AC3: best for home theater systems, DVDs, and cinema soundtracks due to its surround sound capabilities.

Support for advanced features

AAC stands out for its ability to support Scalable Sampling Rates and adaptive bitrates, making it ideal for modern streaming platforms like YouTube, Netflix, and Spotify. This feature allows AAC to dynamically adjust audio quality based on bandwidth availability, ensuring smooth playback even with fluctuating internet speeds. Additionally, AAC supports a wide range of sampling rates and channel configurations, offering flexibility for both low-quality voice recordings and high-fidelity music. AC3, on the other hand, lacks the same scalability, as it is primarily optimized for consistent bitrates and fixed surround sound setups, making it less versatile for adaptive streaming environments.

Licensing and costs

When it comes to licensing, AAC and AC3 differ significantly. AAC is an open standard developed by the MPEG group and, while it may require licensing for certain commercial applications, the general meaning is that it is more accessible and cost-effective for developers and manufacturers. This affordability has led to its widespread adoption across streaming services, software, and mobile devices. AC3, developed and patented by Dolby Laboratories, comes with stricter licensing terms and higher costs. As a result, AC3 is often favored in premium audio environments, such as DVDs, Blu-rays, and cinema systems, where the added cost is justified by its surround sound capabilities.

Energy efficiency

AAC is designed with modern devices in mind, offering superior energy efficiency for portable gadgets such as smartphones, tablets, and laptops. Its advanced compression algorithms allow it to deliver high-quality audio while consuming less processing power, which is crucial for extending battery life during playback or streaming. In contrast, AC3 requires more computational power, particularly when decoding multi-channel audio for surround sound. This increased demand on the hardware can result in faster battery drain, making AC3 less suitable for devices where energy efficiency is a priority.

Convert files on a PC and Mac with Movavi Video Converter

To easily switch between audio formats, Movavi Video Converter is an excellent tool for both PC and Mac users. This user-friendly program supports a wide range of audio and video formats, ensuring seamless and superfast conversion without loss of quality. Whether you need to compress files, convert audio codecs, or optimize files for specific devices, Movavi Video Converter simplifies the process. But users can find it especially useful that the software is not limited to conversion but offers just the right amount of video-editing tools and implies the power of AI to upscale the video resolution.

Summary

Both AAC and AC3 are excellent audio codecs: AAC offers better compression and quality for streaming and mobile devices, while AC3 is ideal for surround sound in home theaters and physical media. To easily convert between these formats or optimize audio for your needs, try Movavi Video Converter. With a free trial, you can explore its powerful features and simplify your media file management.

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