MP3 is a compressed format — fast to download, small to store, but lossy: the encoder discards detail to save space. WAV is uncompressed PCM, which is exactly what your DAW, audio editor, or video editor wants when quality matters. This converter takes any MP3 file and outputs a clean WAV at the source's sample rate, entirely in your browser. No upload, no signup, no preview cap.
MP3 vs WAV — what's the difference?
MP3 (MPEG-1 Audio Layer III) was designed in the 1990s for storage and streaming. It uses psychoacoustic modeling to throw away frequencies the human ear is least sensitive to, typically achieving 10× compression with acceptable quality. WAV (Waveform Audio File Format) is uncompressed — every sample of every channel is stored as raw PCM. WAV files are roughly 10 MB per minute of CD-quality stereo, vs 1 MB for MP3 at 128 kbps. Use WAV when you need to edit, master, or preserve quality. Use MP3 when you need to ship a file.
How this converter works
Your file is decoded by FFmpeg compiled to WebAssembly, running directly in this browser tab. The decoder reads the MP3 frames, decompresses them to floating-point PCM samples, and re-encodes the result as 16-bit signed PCM in a WAV container. There is no server step — your audio data never leaves your device. The same FFmpeg build powers professional audio tools; the WebAssembly version is functionally identical to the native build, just sandboxed in the browser.
When to use this tool
- Editing in a DAW that doesn't accept MP3 input (rare but happens)
- Importing into video editing software with strict format requirements
- Sending masters to a manufacturing facility that requires WAV
- Preserving a finished mix in lossless form before further processing
- Decoding once so you can apply lossy compression at a different bitrate later
Frequently asked questions
- Will the WAV sound better than the MP3?
- No. Converting MP3 to WAV does not restore information that the MP3 encoder discarded. The WAV will be the same audio quality as the MP3, just in an uncompressed container. The benefit of WAV is editability and zero further loss when re-encoding.
- What sample rate and bit depth do I get?
- The output WAV preserves the source MP3's sample rate (typically 44.1 kHz or 48 kHz) and uses 16-bit signed PCM. If you need 24-bit or 32-bit float WAV for mastering, decode in a DAW after this conversion.
- Is there a file size limit?
- 200 MB. That covers comfortably over an hour of CD-quality audio. Larger files are unusual for MP3 sources.
- Does it work on mobile?
- Yes — any modern Chrome, Edge, Firefox, or Safari with WebAssembly support. Mobile is slower than desktop because the encode runs on your device's CPU, but it works.
Privacy
Your file is never uploaded. The decode and re-encode happen entirely in this browser tab, using FFmpeg.wasm and the Web Audio API. We have no server-side audio pipeline because we don't want one — privacy and zero-cost-per-conversion are the entire point of this site.