Loudness Meter (LUFS)
Measure a file's LUFS, loudness range and true peak.
About this tool
Drop in an audio file to measure its integrated loudness, loudness range (LRA), maximum momentary and short-term loudness, sample peak and estimated true peak, with a table comparing it to platform and broadcast targets.
How LUFS loudness is measured
Peak level says how high the loudest sample goes; loudness says how loud the audio actually sounds. Streaming services and broadcasters measure it in LUFS (loudness units relative to full scale) with the ITU-R BS.1770 method used here: each channel is K-weighted (a filter that reduces deep bass and lifts the upper mids, roughly matching our hearing), the energy is averaged over 400 ms blocks, blocks quieter than −70 LUFS are discarded, and then anything more than 10 LU below the average is gated out, so pauses don't drag the number down (EBU R128). The result is the integrated loudness of the whole file. The loudness range (LRA, EBU Tech 3342) shows how much the level varies between quiet and loud parts, and the true peak is estimated by 4× oversampling to catch peaks that fall between samples, which can clip after MP3 or AAC encoding. Spotify, YouTube, Amazon and Tidal aim for about −14 LUFS, Apple Music −16, podcasts −16 (stereo) or −19 (mono), and EBU broadcast −23; louder files are simply turned down. The meter is checked against EBU test signals (a −23 dBFS stereo sine reads −23.0 LUFS). Platform targets can change, and this tool measures but doesn't alter the file. The audio normalizer adjusts level, and the audio waveform tool shows the shape.
Frequently asked questions
What LUFS should I master to for Spotify?
Spotify normalises to about −14 LUFS integrated with peaks below −1 dBTP. Louder masters are turned down, not rejected.
What is the difference between LUFS and dB?
dBFS measures signal level, such as a peak. LUFS measures perceived loudness over time, weighted for human hearing.
What is true peak?
The highest level of the reconstructed waveform, including peaks between samples. Keeping it under −1 dBTP avoids clipping after encoding.
What is a good loudness range?
Pop and podcasts are often 4–8 LU; classical and film can exceed 15 LU. Very low values mean heavy compression.
Is my file uploaded anywhere?
No. Everything is processed in your browser on this device; nothing is uploaded or stored.