FLAC (Free Lossless Audio Codec) is a lossless format: it compresses audio data yet returns to exactly the original data when decoded. It takes up less space than PCM formats such as WAV, and unlike MP3 or AAC it does not throw information away during conversion.
What lossless compression means
FLAC reduces size by recording the arrangement of the data efficiently. Expanding it restores the same state as the original PCM data, so it compresses without changing the sound. However, if the source was MP3 or AAC, the information already lost is not recovered.
Difference from WAV
A typical PCM WAV is the uncompressed reference file that is easy to handle for production and editing. FLAC keeps that same ability to return to the original while taking up less space. Whether your DAW or the delivery destination accepts FLAC is a separate thing to confirm.
Difference from MP3 and AAC
MP3 and AAC are lossy formats for making light files. FLAC tends to be larger than either, but in exchange it returns to a state identical to the original PCM data. Choose by purpose: MP3 or AAC when data usage and player support come first, FLAC when you want to store or deliver the audio unchanged.
Metadata and compatibility
FLAC can carry information such as sample rate and channel count, plus metadata like track and artist names and images. But not every playback device, distribution service, or video editor supports FLAC. Check what the recipient wants before handing over files, and prepare a WAV or another format if needed.
Deciding when to convert
Even when you create FLAC files for long-term storage, keep the projects and WAV files your production is based on. File size varies with the material and the settings, so do not count on a fixed compression ratio. To create WAV and FLAC versions for different purposes, use the audio format converter.
