Perez Philippe has released a free, open-source batch loudness analysis and normalization tool for Windows and macOS.
LUFScale analyzes each file over its full duration, then physically adjusts perceived loudness toward a chosen LUFS target while controlling True Peak, re-measuring the output afterward to confirm the result rather than relying on tags or a compatible player. Originals are never modified, and results are written to a separate destination with the folder structure preserved.
LUFScale features
- Three operations: Normalize (re-encodes toward the LUFS target and True Peak limit), ReplayGain (writes gain metadata without touching audio samples), and Analyze only (measurement with no audio output).
- Adjustable LUFS target and True Peak ceiling for different delivery destinations.
- Automatic re-measurement of every normalized output, with results outside tolerance flagged.
- Track mode for processing files independently, or Album mode for measuring a folder and applying one shared gain across it.
- Byte-for-byte copying when a file already sits within ±0.5 LU of the target and under the True Peak ceiling.
- Local processing with no cloud dependency, a CSV report of measurements and statuses, and resume support that skips already-completed work.
LUFScale supports MP3, FLAC, WAV, AIFF, M4A, OGG, and Opus, and is distributed under the GNU GPL-3.0-or-later license with source available on GitHub.
LUFScale is available to download in both installer and portable editions.
More information: LUFScale
