MP3Gain

Name: MP3Gain
Availability: InStock
Author: Glen Sawyer

MP3Gain is an open source tool that normalizes the volume of MP3 files so they all play at a consistent loudness. Instead of peak normalization (which can still leave songs at different perceived volumes), it uses ReplayGain analysis to match the perceived loudness of each track.

What it does

You load MP3 files into the program, click Track Analysis, and it calculates the perceived loudness of each file. Track Gain adjusts each file individually to a target volume. Album Gain preserves the intended volume differences between tracks on the same album while normalizing across albums.

The modification is lossless and reversible - MP3Gain adjusts the global gain field in the MP3 header without re-encoding the audio data. An Undo function restores original volume levels. Batch processing handles entire music libraries.

Advantages

Lossless volume normalization without re-encoding
Perceived loudness matching (not just peak normalization)
Album mode preserves artistic volume differences
Reversible changes with undo

Drawbacks

Not actively maintained since 2018
MP3 only - does not handle FLAC, AAC, or other formats
Interface is very basic
foobar2000 with ReplayGain or Loudgain handle multiple formats

Who it is for

MP3Gain is for anyone with an MP3 music library where volume levels vary between tracks. For multi-format libraries, foobar2000 applies ReplayGain tags to FLAC, MP3, AAC, and other formats. Loudgain is a modern command-line tool supporting ReplayGain 2.0 for multiple audio formats.

Frequently Asked Questions

What does MP3Gain do?

Normalizes the perceived volume of MP3 files using ReplayGain analysis. It adjusts the MP3 header without re-encoding, so changes are lossless and reversible.

Is MP3Gain better than peak normalization?

Yes. Peak normalization adjusts based on the loudest moment, but perceived loudness can still vary. MP3Gain uses psychoacoustic analysis for consistent perceived volume.

What normalizes FLAC and other formats?

foobar2000 applies ReplayGain tags to FLAC, MP3, AAC, and more. Loudgain is a modern command-line tool. Most streaming services normalize volume automatically.

Features & How-To Guide

#	Feature	How to use
1	MP3 file volume normalization	Add files › Track Analysis › Track Gain › Apply. MP3Gain normalizes volume to target dB value.
2	Audio volume analysis	Add Files › Select files › Track Analysis. Displays current volume in dB and suggested change.
3	Lossless volume modification	MP3Gain modifies volume without re-encoding the file. Changes only MP3 frame headers - no quality loss.
4	Album volume normalization	Add Files › Add all tracks from album › Album Analysis › Album Gain. Preserves volume ratios between tracks.
5	Target volume setting	Target Normal Volume › Enter value in dB (default 89.0 dB). All files will be normalized to this value.
6	Volume change undo	Select files › Modify Gain › Undo Gain Changes. Restores original volume saved in APE tags.
7	Maximum normalization without clipping	Modify Gain › Apply Max No-Clip Gain. Raises volume to maximum level without clipping.
8	Batch processing 4	Add Folder › Select folder with music › Track Analysis › Track Gain. Processes hundreds of files at once.
9	Display clipping information	After analysis the Clipping column shows whether the file will have clipping after normalization. Red icon = clipping.
10	Fixed volume adjustment	Modify Gain › Apply Constant Gain › Enter change value in dB (e.g. +3 or -5). Changes volume by a fixed amount.
11	Analysis result export to file	File › Export Analysis Results. Saves volume analysis report for all files to a text file.
12	APE and ID3 tag support	MP3Gain saves original volume values in APE tags. Tags can be removed via Remove Tag Info.