How do I convert WAV to MP3?

Leave From on WAV and To on MP3, press Open audio or drop the WAV on the stage, choose a bitrate, press Convert and then Download. The MP3 keeps the WAV's name with the new extension.

Which bitrate should I choose?

192 kbps is a practical default; use 256 or 320 kbps when preserving more detail matters, and 96 or 128 kbps for smaller speech files.

Does the original WAV leave my device?

No. Reading, encoding and downloading happen locally.

WAV to MP3 Converter

Choose a WAV, set the MP3 bitrate and encode a compact file in this tab. The source stays local and the page shows the output estimate before conversion.

Open a WAV or FLAC file

· or drop one anywhere on the stage

Never uploadedNo accountUp to 50 MBUp to 10 minutes

From · opens WAV or FLAC

Bitrate

Sample rate

Channels

Download

Ready. Choose a WAV or FLAC file, or drop one on the stage.

A WAV is read as PCM, and 24-bit samples are scaled by 2^23 into the encoder rather than truncated. A FLAC opens here too, unpacked by this browser's own FLAC decoder. The output is a constant bitrate MP3 at the bitrate you choose, which is a lossy encode of what came in.

What the bytes sayread from the first bytes of the file, never from its extension
Open a file and its container is identified before anything is decoded.
Output sizeexact arithmetic for PCM, an estimate for MP3
Open a file to size the output.
Decoderasked of this browser before a conversion starts
A codec with no decoder here is named up front, not halfway through.

The From control is a mode, not a guess: the first bytes of the file are read and checked against it, so a file that was renamed is refused with what it actually is. A bare AAC opens in M4A mode, and a MOV or WebM video in MP4 mode. An MP4 has its audio tracks listed before anything is extracted and its video is never decoded. Changing the sample rate resamples by linear interpolation, and changing the channel count averages a stereo pair down or copies a mono channel to both sides.

Two open source parts do the heavy lifting. Containers are parsed and audio is decoded by Mediabunny 1.55.7 under the MPL-2.0 (licence text, the exact package, source). MP3 encoding is lamejs 1.2.7 under the LGPL-3.0 (licence text, the exact package, corresponding source). Both are bundled unmodified at those versions and loaded from this page, never from another service.

Common questions

How do I convert WAV to MP3?: Leave From on WAV and To on MP3, press Open audio or drop the WAV on the stage, choose a bitrate, press Convert and then Download. The MP3 keeps the WAV's name with the new extension.
Which bitrate should I choose?: 192 kbps is a practical default; use 256 or 320 kbps when preserving more detail matters, and 96 or 128 kbps for smaller speech files.
Does the original WAV leave my device?: No. Reading, encoding and downloading happen locally.

Files are decoded and re-encoded in your browser, so nothing is uploaded. Converting cannot restore detail a lossy file already lost, and an MP3 output is a lossy encode of its own. Which formats can be decoded depends on your browser, and this page checks the file's actual bytes and its codec before starting rather than trusting the extension.