FLAC Converter

FLAC (Free Lossless Audio Codec) shrinks audio to roughly half the size of WAV without losing a single sample, and keeps tags and cover art. This converter makes FLAC from WAV, AIFF, Apple Lossless and other formats, re-compresses FLAC at another level or bit depth, or turns FLAC into WAV, MP3 or Apple Lossless (M4A). It runs in your browser; your files are never uploaded.

How to use this tool

1. Choose one or more audio files.
2. Pick the output: FLAC, WAV, MP3 or Apple Lossless.
3. For FLAC, choose the compression level (5 is standard, 8 the smallest) and keep the bit depth unless a device needs 16-bit.
4. Press Calculate and download the files (several come as one ZIP).

Formula

FLAC size ≈ 50–70% of the WAV size · WAV size = sample rate × channels × bytes per sample × seconds

FLAC and Apple Lossless are encoded by the ffmpeg engine (about 30 MB, downloaded once). Every compression level decodes to the identical samples; higher levels only search harder for a smaller file. When a FLAC is re-encoded with the same sample rate, channels and bit depth, the audio MD5 stored in both files is compared to prove the samples are bit-identical. WAV and MP3 outputs are made by your browser's decoder with our WAV writer or LAME; lossy outputs are checked for clipping after encoding.

Example

A 4-minute CD-quality WAV (44.1 kHz, 16-bit stereo) is 42.3 MB. As FLAC at level 5 it is typically 22–30 MB, depending on the music; level 8 saves another few hundred kilobytes. Converted back to WAV, it is exactly the same 42,336,044-byte file of samples.