What Is LUFS? Loudness for Streaming Explained
Updated October 2026 · by Loopin
LUFS stands for Loudness Units relative to Full Scale. It is the standard way to measure how loud a piece of audio sounds to a listener, rather than how high its waveform reaches. The measurement is defined in ITU-R BS.1770 and used by the EBU R128 broadcast standard, and it is the number Spotify, Apple Music, YouTube and most other services use when they decide how far to turn your song up or down.
This page is the plain-English reference: what the different LUFS readings mean, how LU relates to dB, what each platform does with your track, why true peak matters as much as loudness, and the mistakes that cost people the most.
Why peak meters don't tell you how loud a song is
A peak meter shows the highest sample in the file. Two songs can both peak at −0.1 dBFS and still sound miles apart, because one is a sparse acoustic take with a single loud strum and the other is a dense, compressed pop record that sits near the top the whole way through. Our ears respond to energy over time, and they are more sensitive to the upper mids than to deep bass.
LUFS accounts for both. It applies a frequency weighting that roughly follows human hearing (called K-weighting), measures energy over time, and ignores near-silence so a quiet intro does not drag the figure down. That is why it became the basis for loudness normalisation.
Integrated, short-term and momentary loudness
A loudness meter usually shows three LUFS readings. They use the same scale but different time windows:
- Integrated loudness is the average over the whole track, with gating so silence and very quiet passages are left out. This is the number platforms normalise to, and the one people mean when they say a master is “−14 LUFS”.
- Short-term loudness uses a 3-second sliding window. It is useful for comparing sections: a chorus might read −9 LUFS short-term while the verses sit at −13.
- Momentary loudness uses a 400 ms window and jumps around with every hit. It is useful for spotting a single moment that leaps out, less useful for judging a master.
If you only track one number for release, track integrated loudness. If a song feels uneven, look at short-term readings across the sections.
LU vs dB
A LU (loudness unit) is a relative step on the loudness scale, and one LU equals one decibel of level change. If your master measures −10 LUFS and a platform plays music at −14 LUFS, it turns your track down by about 4 dB, which you can also describe as 4 LU. LUFS is the absolute reading (relative to digital full scale); LU is the difference between two readings. LKFS, used in the US ATSC standard, is the same scale under another name.
What streaming platforms do with your track
Most services use loudness normalisation: they measure your track's integrated loudness and change the playback volume so songs sit at a similar level. The file itself is not changed, and normalisation does not compress or remaster anything, with one exception noted below. The figures below were checked in October 2026; services change their behaviour, so confirm with each platform's own documentation before relying on them. Figures labelled community-measured come from independent testing rather than the platform.
| Service | Plays music at about | What it does |
|---|---|---|
| Spotify | −14 LUFS (Normal, the default) | Turns louder tracks down. Turns quieter tracks up only as far as their peak headroom allows. The listener's Loud setting (about −11 LUFS) uses a limiter; Quiet is about −19. |
| Apple Music | −16 LUFS | Sound Check turns tracks up or down to match. |
| YouTube | −14 LUFS | Turns louder tracks down; does not turn quiet ones up. Community-measured. |
| Amazon Music | −14 LUFS | Community-measured. |
| Tidal | −14 LUFS | Community-measured. |
| Deezer | −15 LUFS | Community-measured. |
| SoundCloud | No confirmed target | SoundCloud has not confirmed loudness normalisation. |
| TikTok, Instagram | Not published | Varies; no stated target. |
| Broadcast | −23 LUFS (EBU R128) / −24 LKFS (ATSC A/85) | Programme loudness for TV and radio, not music streaming. |
So −14 LUFS is a common reference point, not a rule every service follows. It is a sensible place for a streaming master because it sits at or near several of the big services, but a dense rock or trap record mastered at −9 LUFS is not “wrong”; it will simply be turned down, and you should judge whether it still sounds good at the lower level. For per-platform advice, see how to master for Spotify, Apple Music and YouTube.
True peak and the −1 / −2 dBTP ceiling
True peak, measured in dBTP, is the highest level of the reconstructed waveform between samples. When a file is converted to sound, or encoded to MP3 or AAC, the signal can rise above any individual sample value. A master whose samples stop at −0.1 dBFS can still reach above 0 dBTP and distort after encoding, even though your DAW's ordinary peak meter looks fine.
Spotify asks for true peak below −1 dBTP, and for masters louder than −14 LUFS integrated it advises −2 dBTP, because louder masters tend to distort more once they are encoded. A practical rule: about −1 dBTP for a master around −14 LUFS, and −2 dBTP once you push to −11 LUFS or louder.
Loudness range (LRA)
Loudness range, shown in LU, describes how much the loudness varies across the track (EBU Tech 3342). A heavily limited EDM drop might read 3 to 5 LU; a film score or an acoustic ballad can read well above 10. LRA is not a target and no streaming service normalises to it. It is a way to see how much movement survived mastering: if your LRA collapses after mastering and the song sounds tiring, you have probably pushed it too hard.
How to measure your own track
You don't need a metering plugin to check a file. The free Loopin LUFS and true-peak meter reads integrated loudness, short-term and momentary maximums, loudness range and true peak, and shows what each platform in the table above would do to your track. Measure your reference songs the same way, so you are comparing like with like.
If you want the loudness handled for you, Loopin Mastering sets loudness to suit the feel you pick (for example about −14 LUFS for Crisp or Wide, about −11 for Punchy, about −16 for Cinematic) and keeps true peak under the ceilings above, free and in your browser.
Try it now: open the free Loopin Mastering tool — drop in an MP3 or WAV, pick a feel, and download a streaming-ready master. Nothing leaves your device.
Common LUFS mistakes
- Mastering as loud as possible “to compete”. On services that normalise, the louder master is turned down to the same level and keeps only the side effects: flattened transients and less punch.
- Reading short-term loudness as the final number. A chorus at −9 short-term does not make a −9 LUFS master. Use the integrated figure.
- Ignoring true peak. A track that hits its loudness target but peaks above 0 dBTP can crackle after encoding.
- Assuming every platform uses −14. Apple Music sits around −16, Deezer around −15, and SoundCloud has no confirmed normalisation.
- Comparing mixes at different volumes. Louder almost always sounds better for a few seconds. Level-match before you judge, which is what a loudness-matched A/B is for.
- Measuring the mix instead of the master. Leave a few dB of headroom in the mix and judge loudness on the mastered file.
Frequently asked questions
What does LUFS stand for?
Loudness Units relative to Full Scale. It measures perceived loudness over time, as defined in ITU-R BS.1770.
Is −14 LUFS the right target for every song?
No. It is a common reference because Spotify, YouTube and several other services play music at about −14 LUFS, but Apple Music sits around −16 and many commercial genres are mastered louder. Pick the loudness that suits the song, then check it still sounds good once a platform turns it down.
Will Spotify turn up a quiet master?
On the default Normal setting, only as far as the track's peak headroom allows, so a quiet master with high peaks may still play below −14 LUFS. YouTube does not turn quiet tracks up at all.
What true peak should I master to?
About −1 dBTP for a master around −14 LUFS. Spotify advises −2 dBTP for masters louder than −14 LUFS integrated.
What is the difference between LUFS and LU?
LUFS is an absolute loudness reading; LU is the difference between two readings. One LU equals one dB of level change.
How do I check the LUFS of a song?
Run the file through a loudness meter that reports integrated loudness and true peak, such as the free Loopin LUFS meter, and read the integrated value for the whole track.