Most Bluetooth codecs are lossy, which means that the audio data is compressed and not as high quality as lossless audio. This can be a disadvantage for audiophiles, which is why they stay away from wireless headphones. ALAC (Apple Lossless Audio Codec) is an exception because it is a lossless codec that promises higher quality than MP3. Some Bluetooth codecs also promise lossless compression, such as LDAC, but do not live up to their promises.