Audio converter
Convert MP3, M4A, FLAC, Ogg and WAV files to MP3 or WAV without uploading them. Processing stays on your device.
Runs in your browser
Lower is better and larger. LAME’s own VBR scale.
Pick an audio file. It is converted on your device.
Reading and writing are different capabilities
The browser can read MP3, M4A/AAC, FLAC, Ogg and WAV when its own media stack supports that format. Toolfree decodes them to a consistent 44.1 kHz working buffer.
It can write MP3 and WAV here. Web Audio has no file encoder: WAV is serialised directly from the samples, while MP3 comes from a self-hosted LAME WebAssembly module loaded only when needed. The decoded-memory figure beside the file information is useful because compressed audio can grow dramatically once it becomes raw PCM.
Choosing an output
MP3 is the practical choice for sharing, car stereos and older software. It is lossy, so converting an already compressed source introduces another generation of loss.
WAV is uncompressed and suited to editing software. It preserves the decoded working samples without another lossy pass, but the file is usually much larger and a source at another rate has already been resampled to the 44.1 kHz working rate.
The MP3 quality control uses LAME’s VBR scale: 0 is best and largest; 9 is smallest and lowest quality. Four is a balanced default.
Common conversions
- M4A to MP3 — voice memos and phone recordings
- WAV to MP3 — reduce an uncompressed recording for sharing
- FLAC to MP3 — make a portable copy of a lossless source
- Ogg to MP3 — support players that do not understand Ogg
- MP3 to WAV — feed software that expects uncompressed audio
No upload
Decoding and encoding happen in this page. Private recordings stay on the device, and the limits for a long file come from local memory and processing power rather than upload bandwidth.