Video & Audio
Audio Converter
Convert audio between formats and change the bitrate.
A voice memo that needs to become a clean WAV for editing, or a large recording that needs to shrink down for email — both are “convert the audio”, and the browser's own audio engine can already decode almost anything you will throw at it.
This decodes the source file with the Web Audio API, optionally resamples it, and then writes either a real, hand-built WAV file (instant, lossless) or a compressed WebM file using the Opus codec at a bitrate you set (which takes real time, because it is recorded through the browser's own encoder rather than a bundled library).
How to use it
- Choose an audio file — MP3, WAV, M4A, OGG and most other common formats will decode.
- Pick WAV for a lossless, instantly-ready file, or WebM (Opus) for a smaller, compressed one.
- Set the sample rate, and if you chose WebM, the bitrate — higher numbers sound better and produce a larger file.
- Press Convert. WAV finishes immediately; WebM takes about as long as the audio itself, since it is encoded in real time.
- Preview the result, then press Download.
Questions
Can this convert to MP3?
No — browsers have no built-in MP3 encoder, and adding one would mean bundling a large third-party library into a tool meant to stay light. WAV (lossless) and WebM/Opus (compressed, and supported almost everywhere audio is played) cover the two situations an MP3 is usually asked for.
Why does WebM export take real time but WAV does not?
WAV is just the decoded audio samples with a header — no encoding step, so it writes instantly. WebM's Opus codec is only available in the browser's own real-time encoder, reached by actually playing the audio and recording that stream, which necessarily takes as long as the audio's own duration.
What happens if I raise the sample rate above the original?
The audio is resampled up, but no extra detail is created — it will sound the same as the original, just stored at a higher rate. There is no benefit to setting a sample rate higher than the source.