How This Audio Converter Works
What this converter does
This tool takes an audio file and re-encodes it into either MP3 or WAV. It accepts a broad range of inputs — MP3, WAV, OGG, AAC, M4A, FLAC, and WebM — and decodes them with the audio decoder built into your browser, which turns the compressed source into raw audio samples. From those it writes a fresh file in the format you pick, applying your chosen sample rate and channel layout.
MP3 output is written by an MP3 encoder that runs inside the page, while WAV is written as uncompressed 16-bit PCM. Files up to 500MB are accepted, and the decode-and-encode pass runs on your own device without an upload.
When to use it
Reach for it when a file is in a format your target app or device will not play, or when you want a smaller, more portable copy. A frequent case is converting voice memos or downloaded tracks that arrive as M4A or FLAC into MP3, which nearly every player and phone handles.
It is just as useful in the other direction: exporting a WAV from a compressed source when you need an uncompressed file for editing, or collapsing a stereo track to mono when one channel is all you need — for WAV that also halves the file. Tuning bitrate or sample rate to hit a size or quality target is part of the same step.
Example: an M4A lecture to MP3
Say you have a one-hour lecture recorded as an M4A file. Choose MP3 as the output and set the bitrate to 128 kbps, which is plenty for speech. Your browser decodes the AAC audio inside the M4A and the MP3 encoder writes it at 128 kbps. An MP3's size follows from bitrate and length alone — a little under 1 MB per minute at 128 kbps — so the result is about 55 MB whether you pick mono or stereo. The estimate above the Convert button shows this before you start, and the built-in player lets you check the result.
Formats, quality, and edge cases
Output is limited to MP3 and WAV, which cover the compressed-and-portable versus uncompressed-and-editable split most workflows need. The bitrate options (128, 192, 256, and 320 kbps) apply only to MP3; WAV size is governed by sample rate and channel count. Sample rate can be 44.1 kHz (CD standard) or 48 kHz (the usual choice for video).
A few limits are worth knowing. Choosing mono averages the left and right channels, so it cannot be undone, and a mono original stays mono even if you choose stereo. Very large files can exhaust available memory during decoding, so a shorter clip works better. And if a source uses a codec the browser cannot decode, converting it to a common format first usually clears the problem.