Skip to content
FilmScribe
Audio and speech

What is LUFS?

LUFS (Loudness Units relative to Full Scale) is the unit that measures how loud audio sounds to the human ear, across the whole file. YouTube, Spotify, podcast apps and broadcasters use LUFS to level what they play: YouTube aims at -14 LUFS, and European TV at -23.

Also called: LUFS, loudness, LKFS

Measure my audio Try it with my video
Example

The most common targets

If your audio is above the target, the platform turns it down. If it is far below, it sounds weak next to everything else.

DestinationTargetTrue peak
YouTube-14 LUFS-1 dBTP
Spotify-14 LUFS-1 dBTP
Apple Podcasts-16 LUFS-1 dBTP
Mono podcast-19 LUFS-1 dBTP
TV and radio (EBU R128)-23 LUFS-1 dBTP
Why it matters

Why measure in LUFS

Peak level does not tell you whether audio sounds loud. Two tracks with the same peak can sound very different. LUFS follows perceived loudness, and it is what platforms use to decide how much to turn your video down.

Publishing near the target avoids surprises: no clip that sounds quiet next to the others, and no crushed audio the platform turns down and leaves lifeless.

In FilmScribe

LUFS and FilmScribe

We do not change the volume of your clips or snippets: the audio keeps the level of the recording. To measure loudness and normalize before publishing, the free tool shows LUFS and true peak and adjusts to the YouTube, Spotify, podcast or broadcast target, holding peaks at -1 dBTP.

Measure LUFS and normalize audio See the loudness and true peak of your file, pick a target and download MP3 or WAV, with a before and after. Measure my audio →
In practice

Measuring LUFS without mistakes

  1. 01

    Measure the whole file

    Platforms use integrated loudness, measured across the entire program. A meter reading during one loud passage tells you little, so analyze the exported file from start to finish.

  2. 02

    Measure after encoding

    Converting to AAC or MP3 can push peaks above what the WAV showed. That is one reason -1 dBTP is the usual ceiling, and why you should measure the final encoded file.

  3. 03

    Use a limiter, not just gain

    Turning the gain up to reach -14 LUFS also raises the peaks until they clip. A limiter or compressor raises loudness while keeping peaks under the ceiling.

  4. 04

    Even out voices first

    Integrated loudness can hit the target while one speaker is still much quieter than another. Balance the voices first, then normalize, so viewers do not reach for the volume.

Related terms

See all terms →
Transcription The speech in audio or video written down as text, either verbatim, with every hesitation, or clean and easy to read. Vertical clip A short moment cut from a long video, in 9:16, that makes sense on its own and goes to Reels, Shorts and TikTok. Timecode The address of every frame in a video, written as hours, minutes, seconds and frames: HH:MM:SS:FF.

Frequently asked questions

How many LUFS for YouTube?

YouTube levels playback around -14 LUFS integrated. Audio above that is turned down; audio below plays as is. Keep the true peak under -1 dBTP.

What is the difference between LUFS and dB?

dB measures level at a single instant, like the peak. LUFS measures perceived loudness over time, with a filter that mimics the ear. To compare tracks, LUFS is what counts.

Are LUFS and LKFS the same?

Yes. LKFS is the name used in US standards and LUFS in European ones. One LKFS equals one LUFS.

Captions, clips and paper edits. All in one place.

Upload a video or paste a YouTube link. We transcribe every word with its timing, and you take the result to social media or to your editor.

Try it with my video
See the result on your own recording before adding a card.