Audio Converter: to MP3 or WAV

Free Online Audio Converter: Convert to MP3 or WAV in Your Browser

Convert audio files to MP3 or WAV without installing anything. The conversion is done by your browser: your recordings are never uploaded, so it is safe for interviews, voice notes and private recordings, and there is no waiting for an upload.

How to convert audio

1. Drop one or many files into the box above or click it to choose them.
2. Pick the output format. For MP3 pick the bitrate: 320 kbps is the best quality, 128 kbps gives the smallest file.
3. The conversion starts at once. Download each file, or all of them in one ZIP archive.

What can be converted

The browser reads the source file, so this tool converts everything your browser can play: WAV, MP3, M4A (AAC), OGG, Opus and FLAC, and the sound track of MP4 and WebM videos. Output is always a real MP3 or a real 16-bit WAV file, never a renamed copy. Files that browsers cannot read, for example WMA, DRM-protected files and AIFF in most browsers, are reported with a clear message instead of a broken result.

Stereo and mono are kept, surround sound (5.1) is mixed down to stereo. The sample rate of WAV and MP3 sources is kept when MP3 allows it (up to 48 kHz); everything else is converted to 44.1 kHz, the CD rate. Files can be up to 500 MB and 60 minutes long.

MP3 or WAV: which one do you need?

Converting to MP3 always loses some quality, but at 256–320 kbps most people cannot hear the difference. Converting MP3 to WAV does not bring the lost quality back: the WAV file is bigger and sounds exactly like the MP3. Keep the original WAV (or a lossless FLAC) if you may need it later.

Which MP3 bitrate to choose?

• 320 kbps: the highest MP3 quality, about 2.4 MB per minute.
• 256 and 192 kbps: very good quality, 20–40% smaller; a good choice for already compressed sources such as M4A or OGG.
• 128 kbps: fine for speech, voice notes, lectures and podcasts, about 1 MB per minute.

A higher bitrate cannot improve a lossy source: converting a 128 kbps file to 320 kbps only makes it bigger.

Convert audio on the command line

For scripts and servers the same conversions are done with FFmpeg:

• WAV to MP3: ffmpeg -i input.wav -codec:a libmp3lame -b:a 320k output.mp3
• M4A to MP3: ffmpeg -i input.m4a -codec:a libmp3lame -b:a 256k output.mp3
• MP3 to WAV: ffmpeg -i input.mp3 output.wav

Frequently asked questions

Is my audio uploaded?

No. Everything is calculated in your browser, nothing is sent to a server. You can disconnect from the internet after the page has loaded and the converter keeps working.

Is the converter free? Are there limits?

It is free, with no registration and no watermark. The limit is 500 MB and 60 minutes per file, because the browser has to keep the decoded sound in memory.

How long does it take?

A 5 minute song becomes an MP3 in about 10–15 seconds on an ordinary computer; WAV is much faster. The speed depends on your device, phones are slower.

Why does my file not open?

Some formats (WMA, protected files from old music stores) are not supported by browsers. Try a recent version of Chrome, Edge, Firefox or Safari, or convert the file once with a desktop program.

MP3 encoding: LAME through lamejs (LGPL).