About FLAC and AIFF
FLAC is lossless compression for audio — bit-identical to the source at roughly half the size of WAV. It's the archival format of choice for music collections and masters.
AIFF is Apple's uncompressed audio format — the same raw PCM as WAV in a different wrapper, dating back to 1988. It's still the native interchange format for Logic Pro and much of the mac production world, and converts to WAV with zero quality change.
Converting FLAC to AIFF is lossless in both directions — the audio comes through bit-perfect, so you can convert back and forth without generational loss.
How the conversion works
This tool runs FFmpeg — the same engine behind most media software — compiled to WebAssembly, entirely in your browser. Your file is read locally, converted locally, and saved straight from memory; nothing is ever uploaded, which also means no queues and no server-side file size limits.
The converter itself is a one-time ~31 MB download on your first conversion, cached by the browser afterwards. Once it's loaded, everything works offline.