概述
本指南在最重要的标准上比较MP3和FLAC，以帮助您选择适合您需求的格式。
MP3是通用兼容的；FLAC是无损的，但文件要大得多。
正面交锋比较
音频质量
MP3: MP3通过有损压缩丢失了一些音频数据。
FLAC: FLAC是无损的 - 与原始录音质量完全相同。
Winner: FLAC
文件大小
MP3: MP3文件非常小（每首歌3-10MB）。
FLAC: FLAC文件较大（每首歌20-40MB）。
Winner: MP3
兼容性
MP3: MP3可以在任何设备上播放。
FLAC: FLAC需要现代播放器 - 不被iTunes支持。
Winner: MP3
流媒体
MP3: MP3是播客和广播流媒体的标准。
FLAC: FLAC不被大多数流媒体服务支持。
Winner: MP3
归档
MP3: MP3由于质量损失，不适合归档。
FLAC: FLAC是无损音频的理想归档格式。
Winner: FLAC
Technical Foundations
MP3 (MPEG-1/2 Audio Layer III) is a lossy perceptual codec: it applies a hybrid filterbank and MDCT transform, then uses a psychoacoustic model to identify sounds masked by louder neighboring frequencies and discards them, permanently removing data the listener is unlikely to perceive.[1] FLAC (Free Lossless Audio Codec) is lossless: it uses linear predictive modeling to estimate each sample from previous ones, then Rice/Golomb-codes the residual error. Decoding reconstructs the original PCM samples bit-for-bit.[3][4]
File Size and Fidelity
Because MP3 discards inaudible and some audible information, it reaches very small files, commonly around a tenth the size of the uncompressed source at typical bitrates.[2] FLAC removes only statistical redundancy, so it cannot match that ratio; it usually compresses audio to roughly half its uncompressed size while remaining an exact copy.[3] FLAC can therefore be transcoded repeatedly without accumulating artifacts, whereas re-encoding MP3 compounds quality loss.
Bitrate and Quality
MP3 quality is governed by bitrate, expressed in kilobits per second, and may be constant or variable. Higher bitrates discard less data; many listeners find MP3 transparent at around 256 kbps.[2] FLAC has no quality setting in the same sense: its compression level affects only file size and encoding speed, not fidelity, because the output is always a perfect reconstruction of the input regardless of the level chosen.[4]
Metadata and Standardization
Both formats support embedded metadata: MP3 commonly uses ID3 tags, while FLAC uses Vorbis comments, each storing artist, album, track, and cover art.[1][3] MP3 was developed within the MPEG standardization process; FLAC is an open, royalty-free format maintained by the Xiph.Org Foundation, with its bitstream format documented and frozen for long-term stability.[4]
Compatibility and Applications
MP3 is the most broadly compatible audio format, decodable on essentially any device, which suits podcasts, streaming, and storage-limited use.[2] FLAC suits archiving, high-fidelity listening, and any workflow that may re-encode the audio later, since it preserves the master exactly; its support, while wide, is less universal than MP3, particularly on older hardware.[4]