Audio converter
Convert audio files to MP3 or WAV in your browser — MP3, WAV, OGG, M4A and FLAC in, with optional mono downmix and sample-rate change, several files at a time. Decoding and encoding run entirely on your device; nothing is uploaded.
Open Audio converter →What is the Audio converter?
A free, private audio converter that runs entirely in your browser. Drop in MP3, WAV, OGG, M4A or FLAC files — several at once — and convert them to MP3 (choose 128, 192 or 320 kbps) or lossless WAV. You can also downmix to mono and change the sample rate, which is handy for shrinking voice recordings or preparing audio for transcription. Files are decoded and re-encoded on your own device with the Web Audio API and an in-browser MP3 encoder — nothing is uploaded, and it works offline.
How to use Audio converter
- Add your files — Drop audio files onto the tool or click to choose them. Each file joins the queue below.
- Pick the output — Choose MP3 (and its quality) or WAV. Optionally set a new sample rate or tick Mono to downmix.
- Convert — Click Convert all. Each file is decoded and re-encoded in your browser, one after another.
- Download — A Download button appears next to each finished file. Failed files are marked so you can spot them.
Frequently asked questions
Are my files uploaded to a server?
No. Conversion happens completely inside your browser — the tool works even with the internet disconnected.
Which input formats are supported?
Anything your browser can decode: MP3, WAV, OGG and M4A/AAC everywhere, FLAC in most modern browsers, plus WebM audio from recordings.
Can it convert to M4A, OGG or FLAC?
No — browsers can decode those formats but cannot encode them, so output is MP3 or WAV, which cover almost every use.
When should I change the sample rate or use mono?
For spoken audio, mono at 22 050 or 16 000 Hz makes files far smaller with little audible difference — and 16 000 Hz mono is exactly what speech-recognition tools prefer.
Tips
- 192 kbps MP3 is a good default — near-transparent quality at half the size of 320 kbps.
- Convert voice memos to 16 000 Hz mono before transcribing them with the Speech to text tool.
- Queue a whole folder of files at once — each one gets its own download button as it finishes.