概述
本指南比较AAC和MP3在最重要的标准上，以帮助您选择适合您需求的格式。
在相同比特率下，AAC提供比MP3更好的音质，特别是在256kbps以下。
Head-to-Head Comparison
Audio Quality
AAC: 在相同比特率下，AAC提供比MP3更好的音质。
MP3: 在相同比特率下，MP3略逊于AAC。
Winner: AAC
兼容性
AAC: AAC在Apple设备上原生支持；对Android的支持适中。
MP3: MP3几乎被每个设备和应用程序支持。
Winner: MP3
流媒体
AAC: Apple Music、YouTube和大多数平台使用AAC进行流媒体播放。
MP3: MP3广泛用于播客分发。
Winner: 平局
低比特率
AAC: 在128kbps以下的比特率下，AAC明显优于MP3。
MP3: 在低比特率下，MP3的音质明显逊色于AAC。
Winner: AAC
文件大小
AAC: 在相同比特率下，AAC和MP3的文件大小相似。
MP3: 在相同比特率下与AAC的文件大小相似。
Winner: 平局
Technical Foundations
Both AAC and MP3 are lossy perceptual codecs that exploit psychoacoustic masking, but AAC (Advanced Audio Coding) is the later, more refined design intended as the successor to MP3.[1] MP3 uses a hybrid filterbank constrained by its older architecture, while AAC employs a pure MDCT with longer and more flexible transform blocks, more efficient stereo coding, and improved handling of high frequencies.[2][3] These refinements let AAC code audio more accurately for a given amount of data.
Quality at a Given Bitrate
The practical result is that AAC generally delivers better perceived quality than MP3 at the same bitrate, an advantage most noticeable at low bitrates where MP3's coarser tools struggle.[4] AAC also supports more channels and a wider range of sampling rates than MP3's MPEG-1 origins allowed.[1] Both remain lossy, so neither reconstructs the original signal exactly, and re-encoding either format compounds quality loss.
Standardization and Profiles
MP3 (MPEG-1/2 Audio Layer III) and AAC were both standardized within the MPEG process, AAC as part of MPEG-2 and later MPEG-4.[1][2] AAC defines several profiles for different uses, including Low Complexity (LC-AAC) for general audio and High-Efficiency (HE-AAC) for low-bitrate streaming. MP3 has no comparable profile system. AAC files commonly use the .m4a or .aac extensions and are often carried in an MP4 container.[3]
Compatibility and Applications
MP3's large installed base makes it the most universally playable lossy audio format, a safe default for maximum compatibility.[3] AAC is the default audio format in the Apple ecosystem, on YouTube, and across most streaming services, and is the more efficient choice for new content where target devices support it.[4] Support for AAC is now widespread, though MP3 retains a marginal edge on the oldest hardware.
Both Are Lossy
Because both formats discard data, neither is suitable as an archival master where exact preservation matters; that role belongs to lossless formats such as FLAC or uncompressed WAV. AAC and MP3 are distribution and playback formats, chosen for small size and broad compatibility rather than fidelity to the original recording.[2]