Lossless compression is a compression method where decompressing or decoding the file returns exactly the same audio data you had before compression. FLAC is the best-known example, keeping the original data intact while taking up less space than PCM in a WAV. It is an option when you want to store and distribute audio without losing anything, but check separately whether your playback environment and your delivery target support it.
Why it can reduce the file size
Lossless compression records the regularities and repetitions in audio data efficiently so that the original order can be restored on decoding. Because no information is thrown away, the decoded PCM data matches what you had before compression. The compression ratio varies with the content, the sample rate, the bit depth, and the channel count; it is not a fixed percentage.
FLAC and WAV
A WAV containing PCM is generally uncompressed, which makes it easy to use as the standard for production, editing, and delivery. FLAC is a format that losslessly compresses PCM to save space. Both preserve the original sound, but you need to check whether your DAW, plugins, video editing software, and delivery target accept FLAC.
How it differs from lossy compression
Lossy compression such as MP3, AAC, and Opus discards some information to make files smaller. Lossless compression can be restored to the original, but it generally does not get as small as MP3 or AAC. Choose based on whether file size, preserving the sound, or the recipient’s playback environment matters most.
Organize the originals even for archiving
FLAC can be restored to the original PCM data, but it does not automatically manage your production project, your recording settings, or your export dates. Keep the project and the original files organized, and check the metadata if you need to. If a delivery target specifies WAV, it is safest to build it from your original reference file rather than from the FLAC.
A guide to choosing
Use WAV for material you will keep editing and for specified deliveries, FLAC when you want to store and distribute at a smaller size while preserving the sound, and MP3 or AAC for casual listening and sharing. You can make WAV and FLAC versions with the audio format converter tool.
