Loudness Normalization: What Streaming Does to Your Master
Streaming services turn loud songs down. Upload your mix to read its LUFS and true peak, then compare masters free.
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In short
Loudness normalization is playback gain. A streaming service measures how loud a track is and turns it up or down so songs play at similar levels; Spotify says it doesn't change your audio before playback. Spotify publishes one number, −14 dB LUFS. The Apple, YouTube, Amazon Music and Deezer help pages we read describe the feature without a number. Master for sound, keep headroom, then check your figures here before you export.
What is loudness normalization?
Songs reach a service at different volume levels. Spotify puts it plainly: it uses loudness normalization to balance soft and loud songs for a more consistent listening experience. The service measures each track, compares it with a reference level and applies gain while the track plays. If the file itself is too soft, see make an MP3 louder.
Two measurements matter. One is loudness, which Spotify expresses in dB LUFS and, in its mastering tips, as integrated loudness. The other is true peak, a peak level that is measured separately. The ITU-R recommendation Spotify cites, BS.1770, has a title that names both: "Algorithms to measure audio programme loudness and true-peak audio level". Services that publish guidance talk about a loudness figure to aim for and a peak ceiling to stay under. For Spotify's exact figures, see LUFS for Spotify. To read your own LUFS, see the LUFS meter page.
How streaming services handle loudness normalization
Each row paraphrases the service's own help page, read on 27 October 2026. "No number" means that page didn't state one; it doesn't mean the service has none.
| Service | What its own page says | Number published |
|---|---|---|
| Spotify | Adjusts tracks to −14 dB LUFS during playback; albums are normalized together, individual tracks when shuffled or in playlists; the web player and third-party devices aren't normalized; Premium listeners can choose Loud, Normal or Quiet | −14 dB LUFS (Loud −11, Quiet −19) |
| Apple Music | Sound Check adjusts loudness between songs so they play at the same volume; listeners turn it on or off in the Music settings | No number on that page |
| YouTube | Stable volume is on by default and balances the range between quiet and loud; it isn't available for all videos and is turned off for YouTube Music and official music videos | No number |
| Amazon Music | A Loudness Normalization setting in the Android, iOS and FireOS apps plays all songs at the same loudness level | No number |
| Deezer | A volume normalization feature adjusts sound to keep the same volume across tracks; listeners switch it on or off in the app | No number |
Apple's Apple Digital Masters guide adds detail: Sound Check first determines a track's loudness, stores it in the file's metadata, and uses it to raise or lower each track's volume. It can also set volume per album rather than per song. The guide also names ITU BS.1770 as a similar approach in broadcasting.
What it means for your master
Three points follow from those pages.
Loud masters get turned down. Apple's guide says songs mastered loud will be played back at a lower volume, which can make tracks actually sound weaker. Spotify's track not as loud as others? page says a very dynamic track at −14 dB LUFS keeps its peaks, while a loudly mastered one (it gives −6 dB LUFS as an example) is lowered, and both play at the same perceived loudness.
Headroom still matters. Spotify's mastering tips ask for true peak below −1 dB, or below −2 dB when the master is louder than −14 dB integrated LUFS. Apple's guide recommends at least 1 dB of headroom to avoid clipping when audio is oversampled for conversion.
It isn't uniform. It depends on the service, the app and, often, a listener setting. Spotify's web player doesn't use it, and the Apple, Amazon and Deezer pages describe a setting listeners control. Apple's guide says to master so your tracks capture your intended sound, regardless of playback volume.
How to master for loudness normalization in 3 steps
Measure what you have
Drop your mix on the upload box (WAV, MP3, FLAC or AIFF, up to 200 MB and 10 minutes). In the studio, expand "Audio details & processing report" under the player to read the Original's loudness in LUFS, estimated true peak in dBTP and sample rate.
Choose a sound profile and compare
Pick one of eight profiles (Universal, Fire, Clarity, Tape, Natural, Spatial, Cinematic or Punch), then adjust Intensity in steps of 10 and the low, mid and high EQ in ±6 dB. Switch between Original and Mastered. The two aren't level-matched in the studio, so the louder one can win unfairly. Judge by the figures as well as your ears.
Leave headroom, check the numbers, export
Read the Mastered figures in the report. Members download 24-bit WAV, 16-bit WAV or 320 kbps MP3. The report is measured on the profile's base render. Intensity and EQ changes you make afterwards play and export live but aren't re-measured, so verify the exported file with a dedicated meter before release.
What this tool measures, and what it doesn't
The report gives integrated loudness measured with the open-source pyloudnorm library, an estimated true peak and the sample rate. The true-peak value comes from a four-times oversampled estimate and isn't a certified meter. The tool has no field for a target loudness. Each profile has a built-in goal that rises with Intensity, about −14 LUFS at the default of 50 (−15 for Natural), and a limiter with a −1.5 dB ceiling on the base render. The engine's report note says these goals are experimental starting points, not platform delivery standards. It doesn't simulate any service's playback either.
Where streaming levels matter for your release
- Singles through a distributor. DistroKid offers an optional "Loudness Normalization" extra that adjusts level and headroom to −14 dB integrated LUFS with −1 dB true peak maximum, and skips it if your release is already at optimal loudness (source).
- Albums that rely on contrast. Spotify normalizes an album together, and Apple's guide says Sound Check can set volume per album, so the intended differences between tracks can survive.
- Playlists and shuffle. Spotify adjusts individual tracks there instead of the whole album.
- AI-generated songs. Read the starting figures, then use the Suno mastering or Mureka mastering page.
- Videos. YouTube's help page describes stable volume for videos, and says it's off for official music videos.
Tips for mastering with loudness normalization in mind
- Master for sound first. Apple's guide says to capture your intended sound regardless of playback volume.
- Aim for the published figure only where one exists, such as Spotify's −14 dB integrated LUFS.
- Keep true peak under the ceiling the platform names, and re-check after each change.
- Don't assume one number fits every service. Read each service's own page.
- Keep one high-quality stereo master. Spotify says that is all it needs per track.
Ways to check your master, compared
| Option | What it does | Worth knowing |
|---|---|---|
| This tool | Eight profiles, intensity and EQ; report with LUFS, estimated true peak and sample rate | No target field; no per-service preview; downloads need the $9.90/month membership |
| A loudness meter in your DAW | Measures integrated loudness and true peak | Doesn't master for you |
| A distributor's option | DistroKid's optional adjustment to −14 dB LUFS and −1 dB true peak | Specific to that distributor |
| A person mastering your track | Listens to the whole release | Not automated; you brief them |
The honest limits
- No target setting. You read the figures and adjust; the built-in goals are starting points.
- No streaming-service simulation. The tool doesn't show how any service will treat your track.
- True peak is an estimate. It isn't certified metering.
- Intensity and EQ changes aren't re-measured in the report.
- Presets, not a trained AI model. The home-page FAQ says so.
- Not for you if your file is over 10 minutes or 200 MB, or you need certified measurement.
Loudness normalization FAQ
What is loudness normalization?
It is gain applied during playback so that soft and loud songs sound similarly loud. Spotify says it measures loudness at upload, then applies positive or negative gain while a track plays, without changing your audio tracks before playback.
Does it change my file?
Spotify says it doesn't process or change your audio tracks before playback. Apple's guide describes Sound Check storing loudness information in the file's metadata and using it to raise or lower volume. Your delivered master stays yours.
What loudness do streaming services normalize to?
Spotify says −14 dB LUFS, with Premium listener levels of −11, −14 and −19. The Apple, YouTube, Amazon Music and Deezer pages we read give no number, so we don't state one for them.
Should I still master loud?
Apple's guide says songs mastered loud will be played back at a lower volume, which can make tracks sound weaker. Spotify says loud masters are turned down. Master for the sound you want and check the numbers.
How much headroom should I leave?
Spotify asks for true peak below −1 dB, or below −2 dB if the master is louder than −14 dB integrated LUFS. Apple's guide recommends at least 1 dB of headroom to avoid clipping during conversion.
Can listeners turn it off?
Often. Apple Music has a Sound Check setting, Amazon Music has a Loudness Normalization setting, Deezer has a normalize toggle, and YouTube lets viewers turn off stable volume. Spotify says its web player and third-party devices don't use it.
Can I preview each service's normalization here?
No. The tool doesn't simulate any service. It shows your loudness in LUFS, estimated true peak and sample rate, so you can compare against figures like Spotify's.
Does this tool show LUFS?
Yes. Open "Audio details & processing report" under the player to see loudness in LUFS, estimated true peak and sample rate for the Original and the Mastered version. The Mastered figures describe the profile's base render.
Is it free, and which files work?
Uploading, eight sound profiles, intensity, EQ and original/mastered previews are free, with no sign-in needed to preview. Downloads need the $9.90 USD monthly membership, which renews until canceled. Upload WAV, MP3, FLAC or AIFF up to 200 MB and 10 minutes.
Are my uploads stored?
Mastering runs in your browser, then your source audio, master, settings and report are uploaded for private cloud history. Saved results remain until deletion is requested or storage is discontinued with notice. The Privacy page says audio isn't sold or used to train AI models.
Ready to check your own track?
Upload a mix above, open the processing report and see where its loudness and true peak sit before any service turns it up or down. → AI music mastering
Spotify, Apple, YouTube, Amazon and Deezer are trademarks of their owners. This site is not affiliated with or endorsed by them. Statements were checked on 27 October 2026 and may change.
Last updated: 2026-10-27