MP3
MPEG Audio Layer III
MIME type: audio/mpeg
MP3 is the most widely recognized digital audio format. It uses lossy compression to reduce audio files to roughly one-tenth their original size while maintaining acceptable sound quality for most listeners.
Advantages
- +Universal compatibility
- +Good compression with acceptable quality
- +Small file sizes
- +Supported by virtually every device and app
Limitations
- -Lossy — quality lost during compression
- -Inferior quality to FLAC, AAC at same bitrate
- -Patent issues (expired 2017)
- -No support for high-resolution audio
Common Use Cases
Technical Details
MP3 compression uses a psychoacoustic model to identify and remove sounds that fall below the human hearing threshold (auditory masking). It divides audio into 576-sample frames, applies a Modified Discrete Cosine Transform (MDCT), then quantizes and Huffman-encodes the spectral data. Common bitrates range from 128 kbps (acceptable) to 320 kbps (near-transparent). Joint stereo encoding further reduces size by encoding shared channel information once.
Frequently Asked Questions
What bitrate should I use for MP3?
192 kbps is good for casual listening, 256 kbps is high quality, and 320 kbps is the maximum and nearly indistinguishable from the original for most people. For speech/podcasts, 128 kbps is sufficient.