MP3 (.mp3)
The universal audio format — the most widely used standard for music, podcasts, and audio distribution.
- Extension
- .mp3
- MIME Type
- audio/mpeg
Last updated
What Is an MP3 File?
MP3 (MPEG-1 Audio Layer III) is a lossy audio compression format standardised in 1993. It uses psychoacoustic modelling — exploiting limitations in human hearing — to discard audio data that most listeners cannot perceive, producing files typically 5–10× smaller than uncompressed audio.
How MP3 Compression Works
MP3 applies two key perceptual techniques:
Auditory masking: Sounds that are "masked" by louder simultaneous sounds are discarded. A loud drum hit at 1 kHz makes you unable to hear a quiet sound at 900 Hz at the same moment — that quiet sound's data is removed.
Frequency filtering: The MP3 codec removes frequencies above 16–20 kHz (above the upper limit of most adult human hearing) and filters sub-bass below 20 Hz.
Bitrate Guide
| Bitrate | Quality | File Size/Minute | Use Case |
|---|---|---|---|
| 320 kbps | Near-lossless | ~2.4 MB | Audiophile, archival |
| 256 kbps | Excellent | ~1.9 MB | High-quality listening |
| 192 kbps | Good | ~1.4 MB | General music |
| 128 kbps | Acceptable | ~960 KB | Streaming, podcasts |
| 96 kbps | Noticeable loss | ~720 KB | Voice only |
| 64 kbps | Poor | ~480 KB | Not recommended for music |
MP3 vs Modern Alternatives
| Format | Compression | Quality vs MP3 | Use Case |
|---|---|---|---|
| MP3 | Lossy | Baseline | Universal compatibility |
| AAC | Lossy | Better at same bitrate | Apple devices, YouTube |
| OGG Vorbis | Lossy | Better at same bitrate | Web, gaming |
| FLAC | Lossless | Perfect | Archival, audiophile |
| WAV | Uncompressed | Perfect | Studio production |
Tools for MP3 files
Related terms
Related terms
- Bitrate
The amount of data used per second in a media file — higher bitrate means better quality but larger file size.
- Codec
Software that encodes and decodes digital media — compressing video or audio for storage and decompressing it for playback.
- Lossy Compression
A compression method that permanently discards some data to achieve smaller file sizes — the original cannot be exactly reconstructed.
- Metadata
Data stored inside a file that describes the file itself — including author, creation date, camera settings, GPS location, and more.
- MIME Type
A standardised label that identifies the type and format of a file, used by web servers and browsers to handle files correctly.