What Is LUFS? Audio Loudness Explained
LUFS is how professionals measure loudness. Here's what it means and why every platform uses it.
LUFS in Plain Language
LUFS stands for Loudness Units relative to Full Scale. It's a standard way to measure how loud audio sounds to the human ear — not just how high the waveform peaks. Why does that matter? Because two files can have the same peak level but sound completely different in loudness. A file with one loud crack and lots of silence has the same peak as a file that's consistently loud — but the second one sounds much louder. LUFS measures perceived loudness over time, which is what actually matters when you're listening.
Why Platforms Care About LUFS
Streaming platforms normalize everything to a target LUFS level so listeners don't have to constantly adjust volume between tracks or videos. If your audio is louder than the target, the platform turns it down. If it's quieter, some platforms turn it up (Spotify does, YouTube doesn't). Either way, uploading at the right level gives you the best results: • Too loud → platform reduces it, and your carefully crafted dynamics get squashed • Too quiet → audio sounds thin and low-energy compared to other content • Just right → plays as intended, maximum impact
LUFS Targets You Should Know
• -14 LUFS — Spotify, YouTube, Amazon Music. The most common target for music and video. • -16 LUFS — Apple Music, Apple Podcasts. Slightly quieter, more dynamic range preserved. • -23 LUFS — European broadcast standard (EBU R128). Very conservative, used for TV. • -24 LKFS — US broadcast standard (ATSC A/85). Nearly identical to -23 LUFS. For most creators, -14 LUFS is the safe default. For podcasters targeting Apple, use -16 LUFS.
How to Measure and Adjust LUFS
cut.audio's Volume Normalizer measures the integrated LUFS of your file automatically. Drop your file, and it shows you the current loudness. Pick your target, normalize, and download. The before/after display shows exactly what changed — original LUFS, target LUFS, and the gain applied. No guesswork.
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Open Volume NormalizerFrequently Asked Questions
dB (decibels) measures signal level — how high the waveform goes. LUFS measures perceived loudness over time. A file can peak at -1 dB but have an integrated loudness of -20 LUFS if most of the content is quiet. LUFS is closer to what your ears actually hear.
Yes, functionally identical. LUFS is used in the European EBU R128 standard, LKFS in the American ATSC A/85 standard. The measurement is the same — 1 LUFS = 1 LKFS.
YouTube measures loudness and turns down content that exceeds -14 LUFS, but does not boost quiet content. If your audio is at -20 LUFS, it stays at -20 LUFS — so normalizing before upload is important.