How do I make an MP3 louder?

Normalization adjusts a recording's overall level so it plays at a consistent, predictable loudness. The modern approach is loudness normalization measured in LUFS (Loudness Units relative to Full Scale), which models perceived loudness rather than raw signal peaks — the same EBU R128 methodology streaming platforms use, applied via an analysis pass and gain adjustment (ffmpeg's loudnorm filter is the reference implementation of this approach).

This differs from simple peak normalization, which raises the level until the single loudest sample hits a ceiling. Peak normalization can leave a quiet-but-peaky recording still sounding quiet; loudness normalization targets how loud the material actually sounds, which is why it fixes the classic problems — a library where every album plays at a different volume, or a podcast where the host is loud and the guest is a whisper.

Targets worth knowing: streaming music services normalize to around -14 LUFS, podcasts standardise on -16 LUFS (stereo) to -19 LUFS (mono), and broadcast uses -23 LUFS (EBU R128). Normalizing your files to the target of their destination means listeners never reach for the volume knob, and platform-side automatic adjustment leaves your audio untouched.

Reasons to convert MP3 to MP3 usually come down to compatibility, file-size, or specific feature requirements. Common situations:

• An app or platform only accepts MP3 uploads.
• You need a feature unique to MP3 (e.g. lossless editing, chapter markers, smaller streaming size, etc.) that MP3 doesn't provide.
• You're optimising file size — modern formats often produce smaller files than the older format you started with.
• You need a single archival format across a project so files behave consistently in the same viewer.

1. Open the MP3 → MP3 tool on mp3.now.
2. Drag your MP3 file onto the drop zone, or click Select files. You can drop a whole folder of files at once.
3. The output is fixed to MP3. If the format supports extra options (bitrate, sample rate, channels, volume normalization), tweak them in the options panel.
4. Click Convert. The job runs on our server and finishes in a few seconds for typical tracks.
5. Download the result. Files stay in storage for 24 hours and are then permanently deleted.

The entire flow is free for the first 10 jobs per day with no signup required. A free account doubles that quota; a premium plan removes the limit entirely.

• Podcasts: target -16 LUFS. Music for general listening: -14 LUFS matches streaming norms.
• Normalize after merging or editing, as the final step in the chain.
• Loudness (LUFS) normalization beats peak normalization for perceived-volume consistency.
• Batch-normalize a whole audiobook or lecture series so every file plays at the same level.
• Normalization sets overall level; big within-file volume swings need compression in an editor instead.