MP3 File Format (.mp3)
An MP3 file stores audio encoded with MPEG-1 or MPEG-2 Audio Layer III, a lossy codec that permanently discards sound it predicts a listener won't notice in order to shrink the file to roughly a tenth the size of the original PCM recording.
MP3 at a glance#
| Full name | MPEG Audio Layer III |
|---|---|
| File extension | .mp3 |
| Category | Audio Files |
| Developer | Fraunhofer Institute for Integrated Circuits (IIS) |
| First released | 1993 |
| MIME types | audio/mpegaudio/mp3audio/mpa |
| Compression | Lossy |
| Specification | ISO/IEC 11172-3 (MPEG-1 Audio Layer III) |
| FileFlip support | FileFlip reads and writes this format |
What a .mp3 file can hold#
These are the things a MP3 file either supports or does not, and they are what decides whether a conversion keeps everything or quietly drops something.
| Embedded metadata | Yes |
|---|---|
| Audio | Yes |
| Streaming | Yes |
Strengths and limitations of MP3#
What MP3 does well
- Plays on essentially every device, OS, browser and car stereo made since the late 1990s
- At 320 kbps, most listeners cannot reliably tell it apart from the uncompressed source in a blind test
- ID3 tags embed title, artist, album art and more directly inside the file
- Small enough at 128-192 kbps to stream comfortably over a slow connection
Where MP3 falls short
- Compression is one-way, so audio discarded during encoding cannot be recovered by converting to another format
- Standard MPEG-1 Layer III audio is limited to two channels; surround sound needs the rarely-implemented MPEG-2 extension
- Tops out at 320 kbps, well below what a lossless format like FLAC or WAV preserves
- Older, pre-LAME encoders produced audibly worse results than modern ones at the same bit rate
Pick MP3 when a file needs to play anywhere without a second thought about compatibility.
Convert MP3 to an uncompressed format like WAV only when a downstream tool requires PCM input, keeping in mind that the conversion cannot restore audio the original encoding already discarded.
How to open a .mp3 file#
A .mp3 file opens in the programs below, grouped by the platform you are on. If you would rather not install anything, FileFlip converts MP3 into a format your machine already opens, and it does it in the browser tab rather than on a server.
| Platform | Programs that open it |
|---|---|
| Windows | Windows Media Player, VLC, foobar2000 |
| macOS | Music, QuickTime Player, VLC |
| Linux | VLC, Rhythmbox, Audacity |
| iOS | Music, VLC |
| Android | VLC, YouTube Music |
| Web | FileFlip |
MP3 questions people ask#
Does converting MP3 to FLAC improve the sound quality?
No, converting an MP3 to FLAC does not improve its sound quality. FLAC is lossless, but it can only preserve the audio it's given, and by the time a file is an MP3 the compression has already discarded data permanently. Wrapping it in FLAC afterward just produces a larger file that sounds exactly like the MP3.
Is MP3 still patented?
No, MP3 is no longer patented. The key US patent, 6,009,399, expired on April 16, 2017, and Technicolor, which administered MP3 licensing on Fraunhofer's behalf, wound the licensing program down shortly after. European patents on the format had already expired by 2012.
What plays MP3 files?
Nearly everything plays MP3 files: Windows Media Player and VLC on Windows, Music and QuickTime Player on macOS, the built-in players on iOS and Android, and every modern web browser through the HTML5 audio element. It's the one audio format that never needs a compatibility check.
Does converting MP3 to AAC or another lossy format lose quality?
Yes, converting an MP3 to AAC or any other lossy format loses additional quality. Each lossy codec introduces its own compression artifacts, and decoding an MP3 back to PCM and re-encoding it as AAC stacks the new artifacts on top of the ones already baked in, an effect audio engineers call generation loss.
What bit rate should I use for MP3?
192 kbps is a reasonable floor for MP3 and 320 kbps is the practical ceiling the format supports. Below about 128 kbps, artifacts like a loss of high-frequency detail and 'swishy' cymbals become noticeable on most systems; above 256 kbps the gains over the source are hard to hear even on good equipment.
Converting MP3 files#
Convert MP3 to another format
Convert another format to MP3
Every conversion runs inside your browser. The file is read from your disk, the work happens on your own machine, and nothing is uploaded. How FileFlip works names the engine behind each family and how to verify that for yourself.