Lossless compression: smaller files, identical audio
FLAC packs PCM audio without discarding anything, much as ZIP packs documents. Typical music ends up at 50–70% of the WAV size; quiet, sparse recordings compress more, dense or noisy ones less. Decoding the FLAC later returns every sample exactly.
Unlike WAV, FLAC also has a proper tag system with cover art, which makes it the usual choice for archiving CDs and studio masters.
Compression levels 0, 5 and 8
All levels produce the same audio; they differ only in how hard the encoder searches for a compact representation. In our test recording, level 8 was about 14% smaller than level 0 and took about five times as long, and level 5 was about 6% smaller than level 0; real music usually shows smaller differences. Level 5 is also the default of the official flac tool.
Encoding is fast either way: on a desktop Chrome, level 5 processes about 400 times real time, so an hour of audio takes around ten seconds after decoding.
Verified bit-exact with MD5
libFLAC stores an MD5 checksum of the audio inside every file. The converter also computes the checksum of your WAV's samples before encoding and compares the two. When they match, the result shows "Bit-exact lossless" together with the MD5 value, which any FLAC tool can later use to verify the file.
The check applies when rate, channels and bit depth stay on "Original" and the WAV holds 16- or 24-bit integer samples. Changing a setting or starting from float audio produces a different, intentionally non-identical file, and the badge is not shown.
Tags and cover art
Tags in the WAV's RIFF INFO list are copied into FLAC Vorbis comments (TITLE, ARTIST, ALBUM, DATE, GENRE, TRACKNUMBER, COMMENT). Most WAV files have no cover art, and adding or editing tags inside the converter is not available yet.
If your WAV came from a CD ripper that also wrote an ID3 chunk, the converter reads it too, including the cover picture.
24-bit, high sample rates and 32-bit float WAV
16-bit and 24-bit WAVs keep their bit depth, and any sample rate from 3 kHz to 768 kHz is kept as is, so 24-bit/96 kHz and 24-bit/192 kHz masters stay intact.
This converter writes integer FLAC, so 32-bit float WAV is stored as 24-bit. That is far below the noise floor of any recording, but it is not bit-identical to the float original; keep the float WAV if you need to process it further.