Understanding LUFS and Loudness Normalization: What Musicians Need to Know

Mastering music for streaming platforms requires a solid understanding of LUFS and loudness normalization. These concepts are vital for achieving a polished, competitive sound while navigating the ups and downs of streaming services and there is a lot of misinformation and debate out there. From my perspective, here are the basics.

What Are LUFS?

LUFS, or Loudness Units Full Scale, measure perceived loudness rather than raw amplitude. Unlike traditional dB meters, LUFS account for how humans hear sound, for example by emphasizing midrange frequencies around the range of the human voice over bass or treble. This makes LUFS a more accurate tool for mastering engineers aiming to balance dynamics and clarity.

Key LUFS measurements include:

• Integrated LUFS: Average loudness over an entire track. Unless otherwise specified, this is generally the value being referred to and is what I’ll be discussing in this post.

• Short-term LUFS: Loudness over a 3-second window.

• Momentary LUFS: Loudness over 400 milliseconds.

These metrics can help engineers fine-tune a track’s loudness while preserving its emotional impact during the loudest drops and choruses, where the latter two measurements become more relevant.

What Is Loudness Normalization?

Loudness normalization ensures consistent playback levels across songs on streaming platforms like Spotify or Apple Music. By default, these platforms apply gain adjustments to match their target loudness levels.

The most popular streaming services and their LUFS (Loudness Units Full Scale) targets for loudness normalization are as follows: Spotify, YouTube, Amazon Music, and Tidal generally aim for -14 LUFS integrated, with Spotify also offering user-selectable levels (-19 and -11 LUFS) depending on playback settings. Apple Music targets -16 LUFS, while Deezer uses -15 LUFS.

This normalization process is automatic and is almost always turned on by default:

• Tracks louder than the target are attenuated (turned down).

• Tracks quieter than the target are amplified (turned up).

While normalization prevents listeners from constantly adjusting volume, it also limits control over how your music sounds post-upload and (in worst-case scenarios) can reduce quality.

Here is a mix leveled at -14 LUFS before normalization. You can see the transients as sharp peaks with breathable space and dynamic content around them.

Here’s the same mix at -8 LUFS before normalization. Notice the squashed transients with squared-off peaks and lack of variation between moments.

Now here are the same two mixes after being normalized to -14 LUFS. Notice how much smaller and squashed the -8 LUFS master is after being attenuated -6. This loss of size, dynamics, and clarity is clearly audible and is precisely why many people advocate for sticking by the -14 LUFS standard.

All credit for the above example images goes to Mastering the Mix.

The Upsides and Downsides of -14 LUFS Mastering

Mastering at -14 LUFS aligns with streaming platforms’ targets, ensuring minimal alteration during playback. Benefits include:

• Retained dynamics and transients.

• Avoiding excessive compression or distortion.

• Ensuring streaming services leave your audio alone.

But here’s the catch: most commercially released music isn’t mastered this way. The loudness wars are well and truly alive despite what you may have heard. At -14 LUFS, your tracks will usually sound quieter compared to commercial masters in genres like pop or EDM. This can make them feel less powerful and competitive in playlists or radio rotations.

Why Most Modern Masters Are Louder Than -14 LUFS

Despite normalization standards, many tracks are still compressed (more on that here) and usually mastered at levels ranging from to -10 to -6 LUFS integrated. Engineers do this because it can make your song:

1. Stand Out: Louder tracks often feel more impactful during initial playback.

2. Meet Genre Expectations: Pop, EDM, and rap demand punchy, high-energy masters that thrive at louder levels.

This infograph from Twitter user @iamreddave illustrates the increasing levels of loudness over the decades using data from http://dr.loudness-war.info/

3. Please Clients: Artists and labels often prioritize loudness over strict adherence to streaming recommendations and (as I’ve said before) there is scientific merit to the statement “louder is better.”

In short, a pop single mastered at -8 LUFS may be attenuated on Spotify but will still carry the densely-packed energy and presence listeners expect as most every other pop song on the charts is at -8 or louder. Despite the obvious advantages at hand, streaming services have yet to convince engineers and clients to lower their levels in accordance with loudness standards.

Finding the Right Balance

Mastering isn’t about rigidly following numbers—it’s about serving the music. While the range around -14 LUFS works for some projects and genres which favor dynamics and transparency such as jazz or folk, louder levels remain the norm for most competitive releases. The key is balancing dynamics with genre-specific expectations and client goals.

Ultimately, it’s really not about how loud your track measures on a meter—it’s about how it feels to the listener. Whether you’re crafting a dynamic classical recording or a club banger, mastering should always enhance the emotional connection between artist and audience, keeping technical factors in mind but never catering to numbers over feeling.