MP3 converter
FileReshape's MP3 converter turns WAV, M4A, AAC, FLAC, OGG, Opus, WMA, AIFF and AMR files, and the sound of videos, into MP3 at 128 to 320 kbit/s, using FFmpeg inside your browser. The audio is not uploaded. Songs bought with copy protection (old iTunes M4P files) cannot be converted.
Did a file not convert correctly? E-mail [email protected], ideally with a small sample file, and it will be fixed.
Key facts
- Input: WAV (.wav). Output: MP3 (.mp3).
- Your files are not uploaded: the work is done in your browser, on your own device.
- File size: up to 2 GB per file (the limit of the browser's WebAssembly memory).
- Needs a current browser (Chrome, Edge, Firefox or Safari) on a computer, tablet or phone; nothing to install.
- Free to use, with no sign-up.
Why convert audio to MP3
MP3 is the one audio format that every device plays: car stereos, old MP3 players, smart speakers, website builders and the upload forms of many apps. Recordings often come in other formats: WAV from a recorder or audio editor, M4A from an iPhone voice memo, FLAC from a lossless music download, OGG or Opus from a game or a messaging app, WMA from an old Windows library. This converter reads all of them in your browser with FFmpeg and writes an MP3 with the LAME encoder at the quality you choose, keeping the title, artist and album tags when the original has them. It is handy when a file does not open, when an upload form only accepts MP3, or when a large WAV needs to become small enough to send.
How to convert an audio file to MP3
- Drop the audio file in the box, or click to choose it.
- Check the format and duration shown, and choose the MP3 quality.
- Click Convert to MP3 and save the MP3.
What to know before converting to MP3
Lossless to MP3
WAV, FLAC and AIFF are lossless; MP3 is not. At 192 kbit/s or more, most people cannot hear the difference, but keep the lossless original if you may want to edit or convert the recording again later.
Lossy to MP3
M4A (AAC), OGG, Opus and WMA are already lossy. Converting them to MP3 adds a second generation of compression, so choose a bit rate a little higher than the original's and do not convert back and forth.
Voice memos and phone calls
Recordings from phones and dictaphones are often mono and use a low sample rate. The MP3 keeps the channels and sample rate of the original, and 128 kbit/s is plenty for speech.
Copy-protected files
Music bought from the iTunes Store before 2009 (.m4p) and audiobooks in Audible's .aa and .aax formats are encrypted. They cannot be converted here or with any other honest converter.
About the formats
WAV
WAV is the uncompressed audio format of Windows, introduced by Microsoft and IBM in 1991. It stores the sound exactly as it was recorded, which is why studios, audio editors, samplers and many radio and telephone systems ask for WAV files. The price is size: about 10 MB per minute of CD-quality stereo.
- CD quality is 16-bit, 44,100 Hz, stereo: 1,411 kbit/s, about ten times an MP3 at 128 kbit/s.
- Video and broadcast work usually uses 48,000 Hz instead of 44,100 Hz.
- Converting an MP3 to WAV does not bring back what MP3 compression removed; it only makes the file easy to edit.
- A WAV file can be at most 4 GB, which is about 6.7 hours of CD-quality stereo.
MP3
MP3 is the most widely supported audio format. It was developed at the Fraunhofer Institute in Germany and standardised in 1993, and it plays on every phone, computer, car stereo and website. MP3 makes music about a tenth of its CD size by leaving out sounds people hardly hear.
- 128 kbit/s is fine for speech and podcasts; 192–320 kbit/s is used for music.
- The last MP3 patents expired in 2017, so the format is free to use everywhere.
- Title, artist, album and cover art are stored in ID3 tags at the start of the file.
- MP3 is lossy: every new encode loses a little more, so convert from the original when you can.
Frequently asked questions
Is my audio uploaded?
No. The conversion runs in your browser with FFmpeg compiled to WebAssembly. Your file is read from your own device and the MP3 is saved straight from there.
Which formats can I convert?
WAV, M4A, AAC, FLAC, OGG, Opus, WMA, AIFF and AMR, and the sound track of MP4, MOV, MKV and WebM videos. For videos, the MP4 to MP3 page explains the details.
Will the MP3 keep the title and cover?
Title, artist, album and track number are copied into the MP3's ID3 tags when the original has them. Embedded cover pictures are not copied.
How long does it take?
Usually a few seconds per minute of audio on a computer. The engine (32 MB) is downloaded once the first time you use one of the video and audio tools.