Audio Loudness Range Meter
Decode one audio file locally and inspect a quick, unweighted loudness estimate based on 400 ms blocks.
Audio up to 100 MB and 90 minutes. Measurements stay in this browser.
Choose an audio file to begin.
A QUICK WALKTHROUGH
How to use this tool
- Choose an audio file up to 100 MB and 90 minutes.
- Measure the decoded waveform locally.
- Use the indicative LUFS, LU range, and sample-peak readings as a preflight check.
Fast approximation
Integrated loudness is derived from unweighted mean-square energy. Loudness range is the difference between the 10th and 95th percentiles of finite 400 ms block readings. The peak is the highest decoded sample, not an oversampled true-peak measurement.
Local and bounded
The file is decoded with the Web Audio API and is not uploaded. Input is limited to 100 MB, 90 minutes, and eight decoded channels to bound memory and processing time.
Not a compliance meter
This implementation does not apply ITU-R BS.1770 K-weighting, absolute or relative gating, or inter-sample peak detection. Use a standards-compliant meter for delivery, broadcast, or mastering decisions.
GOOD TO KNOW
Common questions
Is this an exact LUFS measurement?
No. It is an unweighted browser estimate and is clearly labelled approximate.
Does the audio leave my device?
No. Decoding and measurement run in this browser.
Is the peak value true peak?
No. It is the largest decoded sample expressed in dBFS; inter-sample peaks are not measured.