foobar2000 is the gold standard for audiophiles on Windows. Its ReplayGain scanner is fast, accurate, and offers a preview.

Install loudgain via Homebrew on Mac ( brew install loudgain ) or your Linux package manager. Open your terminal and navigate to your music directory.

The -a flag treats the folder as an album. r128gain writes the same REPLAYGAIN_* tags as metaflac , but using a psychoacoustic loudness model that better matches human hearing. This is the for anyone building a library in 2024 and beyond.

For advanced users or automated scripts, metaflac is a command-line tool built into the FLAC package. metaflac --add-replay-gain *.flac 3. Visual Editing: Audacity

Go back to the main converter window, choose as your output format, and select an output folder. Click Convert .

FLAC is a , meaning it is an exact digital replica of the source audio. If an album was mastered in 1990 (low gain) and another in 2020 (high gain), their FLAC files will reflect that difference.