Online Tool Store
Audio Loudness Range Meter
Upload an audio file and measure its integrated loudness and loudness range in LUFS/LU, similar to the metering broadcasters and streaming platforms use for normalization.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
An example reading is shown below — upload your own file to measure it.
Integrated loudness
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Loudness range (LRA)
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True peak (approx.)
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How the Audio Loudness Range Meter works
- Upload an audio file — it's decoded entirely in your browser using the Web Audio API.
- The tool splits the waveform into 400ms blocks and computes the mean-square energy of each.
- Integrated loudness averages all blocks; loudness range compares the 10th and 95th percentile blocks, following the general shape of the EBU R128 approach.
- True peak is approximated from the highest sample amplitude found in the file.
FAQ
What is LUFS and why does it matter?
LUFS (Loudness Units relative to Full Scale) is the standard measure streaming platforms and broadcasters use to normalize playback volume across different tracks, so a quiet acoustic song and a loud pop mix sound similarly loud to the listener.
What does loudness range (LRA) tell me?
LRA measures how much a track's loudness varies over time, in loudness units (LU). A low LRA means the mix is heavily compressed and stays at a consistent level; a high LRA means it has more dynamic contrast between quiet and loud passages.
Is this an exact ITU-R BS.1770 measurement?
No — this tool uses a simplified, unweighted approximation of the official K-weighted, gated LUFS algorithm to give a fast, indicative reading in your browser. For mastering-grade accuracy, use a dedicated loudness meter plugin that implements the full ITU-R BS.1770 standard.
How we compare
| Feature | Online Tool Store | DAW loudness plugin | Manual gain riding by ear |
|---|---|---|---|
| No install, works on any file | ✓ | ✗ | ✓ |
| Broadcast-accurate K-weighted measurement | ✗ | ✓ | ✗ |
Use this for a quick sanity check before export — verify final masters against your streaming platform's official loudness target with a certified meter.