LUFS is the unit streaming services use to measure how loud a song is. Spotify, Apple Music, YouTube and most other services turn every track up or down to roughly the same level, so a listener doesn’t have to reach for the volume between songs. If you know how that works, you can stop guessing how loud your master should be.

The short version: don’t release a song that is quieter than the service’s reference level, and leave about 1 dB of headroom for the peaks. Louder than the reference is fine. The service turns it down, along with every other loud track.

This guide explains what LUFS measures, what the streaming services actually say, and how a limiter with platform targets, sonible’s smart:limit, shows you all of this while you work.

What Is LUFS?

LUFS stands for Loudness Units relative to Full Scale. It measures how loud audio sounds to people, not just how high the peaks go. The measurement filters the audio to match how our ears hear, so a bright, dense chorus scores louder than a deep bass note at the same peak level.

A peak meter tells you the loudest single moment. LUFS tells you how loud the song feels. Two tracks can both peak at 0 dB and sound very different in volume, and LUFS shows that difference.

Loudness meters give three readings:

• Integrated: the average loudness of the whole song, start to finish. This is the number streaming services use.
• Short-term: the loudness over the last 3 seconds. Handy for comparing a verse with a chorus.
• Momentary: the loudness over the last 400 milliseconds.

LUFS figures are negative. -14 LUFS is quieter than -9 LUFS. One LU (loudness unit) is the same step as 1 dB.

True peak

The other number you’ll see is true peak, written dBTP. When digital audio is turned back into sound, or converted to an MP3 or AAC file, the waveform can go higher between the samples than any single sample does. A true peak meter catches those in-between peaks. A master that shows 0 dB on an ordinary peak meter can clip once a streaming service has converted it.

What Spotify Asks For

Spotify is the only big music service that publishes exact figures. Its loudness normalisation page for artists says:

• Tracks are adjusted to -14 LUFS integrated.
• Quieter tracks are turned up to reach -14 LUFS, not just loud tracks turned down.
• Keep true peak below -1 dB. If your master is louder than -14 LUFS, keep it below -2 dB to avoid extra distortion.
• Premium listeners can choose Loud (-11 LUFS), Normal (-14 LUFS) or Quiet (-19 LUFS).
• The web player and third-party devices don’t normalise at all.

Other Streaming Services

The other services normalise too, but most don’t publish a figure.

You’ll see figures like -16 for Apple Music or -15 for Deezer quoted on mastering sites. They come from people measuring playback, and services can change them without notice. The Apple podcast requirements are official, which matters if you make podcast music or intros.

In practice, a master that is no quieter than about -14 LUFS, with true peaks below -1 dB, will play back well on all of them.

Louder Is Fine, Quieter Is the Risk

Most beginners read “-14 LUFS” as a target to hit exactly. It’s closer to a minimum.

If your song is louder than -14 LUFS, Spotify turns it down. That costs you nothing. Every other loud song is turned down by the same rule, so yours ends up at the same volume as theirs. The catch is that if you squashed the life out of the track to get it loud, it’s now just as loud as everything else and flatter. Mastering The Mix points out in its guide to mastering loudness that most of the top tracks on Spotify are still mastered well above -14, so loud masters are normal.

If your song is quieter than -14 LUFS, there are two outcomes, and neither is good. The service turns it up, and to stop the peaks clipping, it may run your song through its own limiter (Spotify uses one in its Loud setting). Or it isn’t turned up, and your song plays quieter than the songs either side of it in a playlist.

sonible say the same in the manual for smart:limit: don’t give up dynamics to make a track loud when it will be turned down anyway, don’t fall below the platform’s reference, and being above it is not an issue.

When you should hit an exact figure

Broadcast is different. TV and radio standards such as EBU R128 in Europe (-23 LUFS) and ATSC A/85 in the US (-24 LKFS) set an actual target, with a small tolerance either side. If you’re delivering music for TV, film or a broadcaster’s own spec, hit the number they give you.

How Loud Should Your Song Be?

• For streaming: no quieter than -14 LUFS integrated. Louder is fine if it still sounds good. Set your limiter’s ceiling to -1 dB true peak, or -2 dB if the master is much louder than -14.
• For a podcast or podcast music: about -16 LUFS, true peak no higher than -1 dB.
• For TV or broadcast: whatever the delivery spec says, usually -23 or -24.
• For a CD or a download: there’s no normalisation, so loudness is a choice about how the song should sound.

Judge your master at matched levels. Turn it down to the same loudness as a reference track before you decide it sounds better. Louder nearly always sounds better for a few seconds, the same trap we cover in Compression for Beginners.

sonible smart:limit: Limiting with Platform Targets

Most limiters show you a gain reduction meter and leave the loudness to a separate meter plugin. smart:limit puts the two together, and it knows what each platform expects.

Publishing Targets

A drop-down in the loudness section lets you pick where the song is going. sonible’s manual lists these:

• Streaming: AES/EBU Streaming, Amazon Music, Apple Music, Apple Podcast, Deezer, iTunes, Pandora, SoundCloud, Spotify, Spotify Loud, Tidal, Tidal Quiet and YouTube.
• Broadcast: AGCOM 219/09 (Italy), ATSC A/85 (US), Disney, EBU R128, EBU R128 s3, GY/T 282-2014 (China), HBO, Netflix and TR-B32 (Japan).

You can also type in your own reference loudness. Each target carries its reference loudness and a recommended true peak.

The plugin handles streaming and broadcast targets the way this guide describes. For a streaming service, everything above the reference shows as a green area on its Loudness and Dynamics grid. For a broadcast standard, only the target and a small tolerance band are green.

What the AI does, and what it doesn’t

smart:limit listens to a section of your song and sets the limiter for you, based on a genre profile or a reference track you load. It sets the limiting from the dynamics that suit the genre, not from the loudness target. sonible’s manual says the publishing target is ignored during this learning step.

So smart:limit won’t make your song exactly -14 LUFS for Spotify. It makes a master with sensible dynamics for the style, then shows you where that sits against the target and how much the service will turn it down. If the loudness is too low, the Quality Check gives you a hint, with arrows showing which control to move: input gain, output gain or the limit line.

The rest of the plugin

• Metering: integrated, short-term and momentary LUFS, loudness range, true peak and a dynamics reading. Instant Impact Prediction updates the readings as you change a setting, so you don’t have to play the whole song again.
• Limit line: drag it to set the true peak ceiling. sonible’s manual suggests at least -1 dB for streaming, for the conversion reason above.
• Sound shaping: a Style dial from soft to hard limiting, Saturation, Balance for the tonal balance and Bass Control for the low end.
• States: store different settings and switch between them to compare.

MusicTech scored it 9 out of 10 and called it good for beginners and pros alike. Its main complaint was that the metering window could be bigger and easier to read.

smart:limit costs $129 at Plugin Boutique and runs as VST, VST3, AU and AAX on Mac (native on Apple Silicon) and VST, VST3 and AAX on Windows. sonible offers a 30-day trial with no limits. Our smart:limit deal page shows when it’s on sale.

learn:limit: the cheaper sonible option

learn:limit is sonible’s newer limiter for people still learning. It uses a similar AI setup but only has three loudness targets: Streaming (-14 LUFS by default), CD and Broadcasting. Three quality indicators for loudness, loudness range and true peak show a green tick when each is in a good range for streaming. A Level Match button plays the limited and unlimited versions at the same loudness, so you hear what the limiter changed rather than the volume jump. It costs $69.

Other Plugins That Do the Job

You don’t need an AI limiter to get this right. Any true peak limiter plus a loudness meter will do it. These are the main alternatives on Plugin Boutique, plus one free meter.

FabFilter Pro-L 2

Pro-L 2 is the choice if you want to set every part of the limiter yourself. It’s a true peak limiter with eight limiting algorithms, up to 32x oversampling and loudness metering for the EBU R128, ITU-R BS.1770-4 and ATSC A/85 standards. There’s no AI and no list of streaming services to pick from, so you read the meter and set the target yourself. FabFilter offers a 30-day trial.

LEVELS by Mastering The Mix

LEVELS doesn’t limit anything. It checks your mix or master and flags problems: integrated and short-term LUFS, a 16x oversampled true peak meter, stereo width and more. Presets for CD, club, streaming and YouTube set what counts as a pass. Put it after whatever limiter you already own.

Loudness Penalty 2 by MeterPlugs

Loudness Penalty 2 shows how much YouTube, Spotify, Apple Music, Amazon Music, TIDAL, Deezer and Pandora will turn your song down. Version 2 copies the limiter Spotify uses in its Loud setting, so you can hear what it would take out of a quiet master before you upload it.

Youlean Loudness Meter

The free version of Youlean Loudness Meter gives you integrated, short-term and momentary LUFS and true peak. With your DAW’s own limiter, it’s enough to follow everything in this guide without spending anything.

LUFS FAQs

What LUFS should I master to for Spotify?

No quieter than -14 LUFS integrated, with true peak below -1 dB. If the master is louder than -14, Spotify suggests keeping true peak below -2 dB.

What LUFS is best for YouTube?

YouTube doesn’t publish a figure. A master that suits Spotify (no quieter than -14 LUFS, true peak below -1 dB) works on YouTube too.

Is -14 LUFS too quiet?

Not on a streaming service with normalisation switched on, because louder songs are turned down to meet it. It can sound quiet on a CD, in a DJ set or in a player without normalisation.

Will Spotify make my loud master sound worse?

It turns the whole song down, which doesn’t change the sound. What hurts a loud master is the limiting you did to make it loud. If it still sounds good, it’s fine.

Does smart:limit set my song to -14 LUFS automatically?

No. Its AI sets the limiting from the genre and the song’s dynamics. The publishing target shows whether the result is loud enough and how much the service will turn it down. You then adjust the gain if you need to.

Do I need a paid plugin to measure LUFS?

No. Many DAWs include a loudness meter, and the free Youlean Loudness Meter covers the readings you need.

Sources

• Spotify for Artists, Loudness normalization.
• Apple Support, If music in Apple Music sounds quiet (Sound Check), and Apple Podcasts for Creators, Audio requirements.
• Deezer Support, Volume Normalization on Deezer.
• sonible, smart:limit manual (Publishing Target, limit line) and learn:limit manual (Settings, Reference Target).
• Plugin Boutique product pages for smart:limit, learn:limit, FabFilter Pro-L 2, LEVELS and Loudness Penalty 2 (8 November 2026).