Glowtrack Studio LUFS Loudness Checker

LUFS Loudness Checker

Check the loudness of your master in LUFS and its true peak, then see what Spotify, YouTube, Apple Music and other services will do to it. Free, in your browser — several files at once, nothing uploaded.

Drop your masters here, or click to choose MP3, WAV, FLAC, M4A, AAC or OGG · several at once is fine
Songs can feel like half or double their tempo — pick a range to steer the result.
No file? Tap the tempoTap the button (or press T) along with the beat — 8 taps or more gives a solid reading.
— BPM
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How it works

  1. Drop in your mastersWAV, FLAC, MP3, M4A or OGG — a single track or a whole album.
  2. Read the loudnessIntegrated loudness in LUFS (as streaming services measure it) and true peak in dBTP.
  3. See each platformA table shows whether each service will turn your track down, turn it up, or leave it — and by how much.

What the numbers mean

Integrated LUFSThe average loudness of the whole track, measured the way the ears hear it (ITU-R BS.1770 / EBU R128). Streaming services compare this to their target.
True peak (dBTP)The highest level the waveform reaches between samples. Above −1 dBTP, MP3 and AAC conversion can clip and distort.
NormalisationServices turn loud tracks down to their target. Most also turn quiet tracks up, but only as far as the peaks allow. YouTube and Apple Music mostly only turn down.
Then why master loud?You don’t gain loudness above the target — it’s simply turned down. You can, however, lose punch by squashing a master harder than needed.

FAQ

Is my song uploaded?

No. Everything is analysed inside your browser on your own device. Your audio is never sent anywhere, so it’s safe for unreleased masters.

What LUFS should I master to?

For streaming, around −14 LUFS integrated with a true peak of −1 dBTP is a safe all-round target: Spotify, YouTube, Amazon Music and TIDAL play at about −14, Deezer at −15 and Apple Music at −16. Many genres are mastered louder (−10 to −8) for impact; that’s fine, it will simply be turned down.

Is this the same LUFS my DAW meter shows?

Yes — it uses the same standard (ITU-R BS.1770 with K-weighting and gating). Results usually match plug-in meters within a few tenths of a dB.

Why does Spotify not turn my quiet track up fully?

Spotify’s normal mode only raises a quiet track as far as it can without its peaks going over −1 dBTP. A quiet master with high peaks stays quieter than the target.

Does YouTube turn quiet videos up?

No. YouTube turns loud audio down to about −14 LUFS but leaves quieter audio as it is, so a quiet mix plays quieter than other videos.

What is the difference between LUFS and dB?

dB peak meters show the loudest instant. LUFS measures perceived loudness over time, so two tracks with the same peak can have very different LUFS.

Is it free?

Yes — free, with no sign-up, supported by the ads on the page.

More free tools

BPM & key finderTempo, key and Camelot code of any song. Audio converterConvert and match streaming loudness on the way. Guide: what LUFS to master toEvery platform’s loudness target in one place.