Integrated Loudness (LUFS) Analyzer
Measure mono/stereo integrated programme loudness with a BS.1770-style K-weighted absolute/relative gating method.
Choose a browser-decodable mono or stereo audio file.
How it works
The decoded mono/stereo signal is K-weighted, measured in 400 ms blocks stepped every 100 ms, then gated with an absolute −70 LUFS threshold followed by a relative gate 10 LU below the absolute-gated mean. The surviving block energies are averaged to obtain integrated loudness.
How to interpret the result
Integrated LUFS is programme-average loudness evidence, not peak level. Different services, broadcasters and workflows may use different delivery targets, and MesraTools does not present one target as universally correct.
Why mono/stereo only?
Correct multichannel loudness depends on trustworthy channel layout and channel weighting. Build 121 refuses to guess from a browser AudioBuffer when that layout evidence is not reliable.
Privacy
This Build 121 analyzer decodes and measures the selected audio in the browser; it does not intentionally upload the file to MesraTools.
Scope and limitations
Build 121 deliberately limits integrated loudness and loudness-range evidence to mono/stereo because browser-decoded multichannel channel-layout metadata is not reliable enough for truthful BS.1770 channel weighting. These results are technical aids, not a broadcast/mastering compliance certificate.
Related tools
Use RMS & Peak Audio Analyzer for mathematical RMS/sample-peak evidence, Clipping & Headroom Analyzer for decoded sample headroom, and Technical Audio Report for broader decoded-signal statistics.