Adjustable target
Choose the LUFS level that fits your destination.
Free and open-source software
Download and use LUFScale at no cost. It is distributed under the GNU GPL‑3.0-or-later license.
macOS 12+ · Apple Silicon / IntelWindows 10 / 11GPL‑3.02.1.12
No more volume jumps between your audio files: analyze and normalize them with precision.
Supported audio formatsMP3 · FLAC · WAV · AIFF · M4A · OGG · Opus
Measured and verified audio normalization
Consistent perceived loudness, file after file.
LUFScale measures the loudness of your files and, with Normalize, physically adjusts their perceived volume toward a LUFS target while controlling True Peak. Each source is analysed over its full duration, then the output is measured again and verified. The result does not depend on tags or a compatible player: levels become more consistent from file to file, deviations are flagged, and originals remain untouched.
LUFS + True Peak
The difference should be heard and measured.
A useful difference must do more than change a graph: it must reduce audible level jumps and remain demonstrable with repeatable measurements. Integrated LUFS describes perceived loudness over time, while True Peak monitors peaks that may overload playback or encoding. LUFScale combines both, then remeasures the output to confirm the target and the chosen ceiling.
True Peak
Set a peak limit and verify the output.
Quality control
Measure each output again automatically.
Local processing
The audio engine runs on your computer.
CSV report
Keep measurements, durations, statuses, errors and warnings with the processed files.
Choose with confidence
Three operations, three clear purposes
Choose exactly what should happen to each file.
Normalize
Re-encodes the audio stream, brings each file toward the LUFS target, and applies the True Peak limit.
ReplayGain
Preserves audio samples and writes suggested gain metadata for compatible players.
Analyze only
Measures loudness and peak without creating an audio output.
macOS + Windows
Choose your platform
Download the ready-to-use edition or the reproducible source build kit. On Windows, choose the recommended Setup or the no-install Portable edition.
macOS 12 or later · Apple Silicon / Intel
macOS
—Count available at launch
Ready-to-use distribution · Apple Silicon (arm64)
Self-contained app: unzip it, move it to Applications, and open it. No Python, Qt or FFmpeg installation is required.
SHA-256
—Ready-to-use distribution · Intel (x86_64)
Self-contained app: unzip it, move it to Applications, and open it. No Python, Qt or FFmpeg installation is required.
SHA-256
—macOS source and compliance kit
Single archive for publishers containing the LUFScale source and build tools, exact FFmpeg and codec sources, licences, notices, and Apple Silicon and Intel release manifests. It is not required to install or run LUFScale.
- LUFScale.app
- Self-contained application for local testing and regular use.
- Community ZIP
- Complete archive for sharing or publication, containing the application, corresponding sources, licences and notices.
SHA-256
—Windows 10 or 11
Windows
—Count available at launch
Setup (Recommended)
Installs LUFScale normally for regular use.
SHA-256
—Portable (No installation)
Runs directly and can be copied to another computer.
SHA-256
—Source build kit
For publishers: fetches verified build prerequisites, packages the app, then compiles the offline installer.
SHA-256
—Practical guides in 12 languages
Download the illustrated PDF for your language and platform. (These guides are already included in the application itself.)
EnglishEN
FrançaisFR
EspañolES
ItalianoIT
PortuguêsPT
РусскийRU
日本語JA
हिन्दीHI
简体中文ZH
한국어KO
Bahasa IndonesiaID
TürkçeTR
Project history
What changed, version by version
A concise, verified history. Open it only when you want the details.
Latest2.1.12View release history
Project history
What changed, version by version
A concise, verified history. Open it only when you want the details.
2.1.12Latest
Visible log and refreshed guides
- Processing-log rendering is restored while compact spacing remains uniform across all scripts.
- The site address is aligned at the right; all 24 PDF guides have corrected page-one layouts.
- The website uses the 12 native language screenshots without enlargement or a coloured frame.
2.1.10
Multiplatform documentation
- Build instructions and exact output paths for Apple Silicon, Intel Mac, and Windows.
- Twenty-four localized macOS and Windows PDF guides regenerated and checked.
- No change to audio processing.
2.1.9
Publication review
- Public sources, documents, guides, metadata, and filenames reviewed.
- Development caches and unrelated files removed from the public archives; runtime unchanged.
2.1.8
Clearer technical guides
- The macOS builder documentation now explains that it resumes automatically after the Xcode tools installation.
- Each automatic-quality-control formula now has its own explanation in all twelve languages.
2.1.7
Versioning correction
- Technical reissue of 2.1.6 with coherent version records.
- No functional change from 2.1.6.
2.1.6
Self-contained builders and portable Windows app
- The macOS builder no longer requires Python, Homebrew, or pkg-config to be preinstalled and resumes after Xcode tools are installed.
- Windows can produce an offline installer and a self-contained portable executable.
- CSV reports and automatic start are off by default on a fresh installation.
2.1.3
Simplified public distribution
- One clear builder at the root of each platform package.
- Public archives, version records, SBOM, and twelve guides cleaned and synchronized.
FAQ
Frequently asked questions
Does ReplayGain physically normalize the file?+
No. It writes gain and peak tags without changing the audio samples. A compatible player applies the gain during playback.
Does Analyze only change my files?+
No. It measures source files and can create a report, but it produces no audio output.
Is −14 LUFS mandatory?+
No. It is a common setting, not a universal rule. LUFScale lets you choose the target and True Peak limit for your destination.
Which audio formats are supported?+
LUFScale supports MP3, FLAC, WAV, AIFF, M4A, OGG, and Opus, including files found in subfolders.
Are my original files ever modified?+
No. Sources remain untouched. LUFScale writes results to the destination and preserves the folder tree.
What is the difference between Track and Album mode?+
Track processes each file separately. Album first measures the folder, then applies one shared gain so the intended differences between tracks are preserved.
When can a file be copied without re-encoding?+
When it is already within ±0.5 LU of the target and remains below the selected True Peak ceiling, it can be copied byte for byte without new quality loss.
How does quality control work?+
Each normalized output is measured again. LUFScale checks the achieved loudness and True Peak, then clearly flags any result outside the accepted tolerance.
What happens if processing is interrupted or restarted?+
Cache and resume data identify unchanged sources, settings, and outputs. Work already completed can therefore be skipped safely when the run resumes.
Why do processing time and CPU usage vary?+
Automatic parallelism adapts the number of simultaneous jobs to CPU load. Cumulative work time across jobs is therefore different from the actual elapsed time.