How to measure LUFS for free (and what to do with the number)
You do not need a paid plugin to know how loud your track is. Here are the free options, from an online meter that takes ten seconds to a DAW plugin, and a short guide to reading what they tell you.
· 4 min read
Option 1: an online meter
Upload the file, get integrated LUFS, true peak, loudness range and PLR back in a few seconds. Our free meter also draws the tonal balance against commercial masters and tells you what each platform will do to the level on playback. Nothing is stored, and there is no account.
Use the WAV you intend to release, not an MP3, so the true-peak reading matches the file the distributor gets.
Option 2: a free plugin in your DAW
Youlean Loudness Meter (free version), dpMeter and the built-in meters in Reaper, Logic and recent Ableton versions all report integrated LUFS and true peak. Put the meter last in the master chain, play the whole song from start to finish, and read the integrated value at the end, not the momentary one.
Option 3: the command line
ffmpeg's loudnorm filter prints integrated loudness, true peak and LRA for any file: `ffmpeg -i song.wav -af loudnorm=print_format=summary -f null -`. It is what many online tools run underneath.
Reading the numbers
| Reading | Means |
|---|---|
| Integrated −15 LUFS, TP −4 dBTP | Typical raw AI export. Quiet, lots of headroom, ready to master. |
| Integrated −14 LUFS, TP −1 dBTP | Streaming-ready master. Plays at full level on Spotify and YouTube. |
| Integrated −9 LUFS, TP −0.1 dBTP | Loud master with no codec headroom. Will be turned down 5 dB on streaming and may clip after encoding. |
| PLR under 8 dB | Heavily limited. Do not compress further. |
The number is only useful next to a target. Decide where the track is going first, then measure.
FAQ
Is a phone app accurate enough?
For integrated loudness, yes, if it implements BS.1770. Most phone apps do not measure true peak correctly; use a desktop or online tool for that.
Why do two meters give different LUFS?
Gating and measurement window differences, usually within 0.3 LU. Bigger differences mean one tool is reading short-term or momentary loudness instead of integrated.
Try it on your own track
Free 60-second preview. No account needed.