Audio / 06
LUFS Loudness Meter
Measure the integrated loudness of an audio or video file in LUFS, with its true peak, and see how it compares with Spotify, Apple Podcasts, EBU R128, and ATSC A/85, without uploading it.
LUFS Loudness Meter: The page measures loudness as ITU-R BS.1770 specifies: K-weighting that mimics how the ear hears, 400 ms blocks, and gating that leaves out silence and quiet passages, as EBU R128 does. The true peak is estimated by oversampling four times, since the waveform between samples can rise above the highest sample. Runs 100% locally in your browser with zero server file uploads.
- Category
- Video tools
- Runs
- In your browser
- Cost
- Free · no sign-up
- Availability
- Ready to use
Runs entirely in your browser
MP3, M4A, WAV, FLAC, OGG, or a video's soundtrack · up to 250 MB, nothing uploaded
Integrated loudness and the other readings
Integrated loudness is a single figure for the whole file, the one streaming services and broadcast specifications use. Mixing engineers also watch momentary loudness (over 400 ms) and short-term loudness (over 3 seconds) while they work, and loudness range, which describes how much the level varies; this meter reports the integrated figure and the peaks, which are what a delivery specification checks.
Reading the comparison
A file within half a loudness unit of a target is shown as on target. A peak over a target's ceiling means the file needs lowering, or a limiter, before it meets that specification, even when its loudness is right. The audio normalizer applies the gain for you and measures the result.
How to use it
- Choose an audio file, or a video to measure its soundtrack.
- Read the integrated loudness, true peak, and sample peak.
- Compare them with the targets in the table, and use the normalizer to adjust.
Privacy & limitations
The file is measured in your browser and never uploaded.
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Frequently asked questions
What is LUFS?
Loudness Units relative to Full Scale: a measure of how loud audio sounds rather than how high its peaks go. One LU is one decibel of loudness, so a track at −14 LUFS is 2 LU louder than one at −16. LKFS, used in the US, is the same measure under another name.
How accurate is the reading?
The measurement follows BS.1770 and reads −23.0 LUFS on the EBU's reference tone at −23 dBFS and −3.01 on the Recommendation's own one-channel test. The browser first converts the file to 48 kHz, so readings can differ slightly from a meter working at the file's own rate; in our tests against FFmpeg's EBU R128 meter the difference was at most 0.1 LU.
What is the difference between true peak and sample peak?
Sample peak is the highest sample in the file. True peak estimates the highest point of the wave rebuilt between the samples, which can be higher, and is what players and encoders actually produce. Streaming and broadcast specifications set their ceilings in true peak.
Why is my quiet intro not counted?
Integrated loudness is gated: blocks quieter than −70 LUFS, and blocks more than 10 LU below the average, are left out, so silence and quiet passages do not drag the figure down. That is how streaming services and broadcasters measure it.
Free tool · runs in your browser · no account required