Audio Converter — to MP3 (and back to WAV)
Convert WAV, M4A, FLAC, OGG and AAC into MP3, or turn an MP3 back into an uncompressed WAV. No upload, works offline, no sign-up. Your audio is converted on your device and never leaves it.
Runs entirely in your browser — your audio is never uploaded.
- No upload Your video never leaves your device — it is processed locally.
- Works offline After the first load it runs with no internet connection.
- No size or daily limits No file caps, no paywalls — only your device memory.
- Private & safe Skip sketchy upload sites; nothing is sent to a server.
How it works
The conversion is handled by ffmpeg compiled to WebAssembly and run inside
your browser. When you choose a file, it is loaded into memory and decoded from whatever codec
it uses — PCM, AAC, FLAC, Vorbis and so on. For MP3 output the audio is re-encoded with the
LAME encoder (libmp3lame) at the bitrate you select; for WAV output it is written
as raw 16-bit PCM (pcm_s16le). Because every step runs client-side, your file is
never transmitted anywhere. The first conversion downloads the engine once (about 9 MB), which
is then cached for instant, offline use afterward.
How to convert audio
- Choose an audio file with the drop zone above, or drag one onto it.
- Pick the output: MP3 for a small universal file, or WAV for lossless.
- If you chose MP3, select a bitrate — 128 kbps for voice, 192 kbps for general use, 320 kbps for music.
- Press Convert audio, then click Download when it finishes.
Audio re-encoding is light work, so most files convert in a few seconds. Very long recordings take a little longer and use more memory because the whole file is processed in the browser.
Why convert audio locally instead of on an upload site
Most audio-converter websites upload your file to a server, convert it there and hand back a link — which is slower over a typical connection, exposes private recordings to a third party, and often comes with size caps or paid tiers. Converting in your browser removes the upload step entirely, keeps the audio private, and has no limits beyond your device memory. It also sidesteps a genuine safety problem: in March 2025 the FBI’s Denver field office warned that some free online file-converter sites were being used to spread malware — so keeping the work on your own machine is simply safer.
| Local (this site) | Typical cloud tool | |
|---|---|---|
| Upload required | No | Usually |
| File-size caps | None (device memory) | Common |
| Works offline | Yes, after first load | No |
| Files stay private | Yes — never sent | Sent to a server |
Common uses
Turning a voice memo recorded as M4A into an MP3 you can share anywhere, shrinking a large FLAC music library to portable MP3s, converting an OGG download so it plays on a device that does not support it, or decoding an MP3 to WAV so it imports cleanly into editing software or a sampler. Because there are no daily limits, you can run through a whole folder one file at a time.
More video & audio tools
Frequently asked questions
Is my audio uploaded to convert it?
No. The conversion runs entirely inside your browser with ffmpeg compiled to WebAssembly. Your file is read into memory on your own device, decoded and re-encoded there, and the result is written locally for download. Nothing is sent to a server, so there is no upload wait and no copy of your audio is stored online.
Which formats can I convert?
You can convert WAV, M4A (AAC), FLAC, OGG/Vorbis, AAC and most other audio ffmpeg can read into MP3. You can also go the other way and turn an MP3 into an uncompressed WAV. The tool decodes whatever codec is inside and re-encodes it to your chosen output, so the source container or codec does not matter.
What MP3 bitrate should I pick?
For voice, audiobooks and podcasts, 128 kbps is small and clear. For general music, 192 kbps is a good balance of size and quality, and 320 kbps is near-transparent for careful listening. Remember that bitrate cannot add detail that the source never had — converting a low-quality file at 320 kbps just makes a bigger file, not a better one.
Will converting FLAC to MP3 lose quality?
Yes, a little, because FLAC is lossless and MP3 is lossy — re-encoding always discards some data. At 192 or 320 kbps the difference is usually inaudible on typical gear, and the file becomes far smaller. If you need to keep every bit, convert to WAV instead, which is lossless but large.
Why convert to WAV — isn’t it huge?
WAV is uncompressed PCM, so files are large, but it is universally supported and lossless, which makes it handy for editing software, samplers, or any app that refuses compressed audio. The MP3-to-WAV path simply decodes the MP3 back to raw PCM; it cannot recover quality the MP3 already lost, but it gives you a clean, editable wave file.
Does it work offline?
Yes. The site is a Progressive Web App, so after the first visit it runs with no internet connection, and the ffmpeg engine is cached after its one-time download so conversions keep working offline.
All processing happens on Video Tools entirely within your browser. Audio is never uploaded to a server.