Sunofix AI 2

Free online LUFS meter

Check how loud your track is. Choose a file to measure its LUFS and peaks, entirely in your browser.

Your track stays on your device. No account or audio upload required.

Measure your track

No upload. No sign-up.

Drag and drop your audio

Drop your track here

WAV or MP3 · mono or stereo · up to 10 minutes · 100 MB maximum

FLAC, OGG, M4A and AAC depend on your browser’s decoder.

Starting the local analyzer…

Your audio stays in this tab’s memory. Clear the file or close this tab to discard the working audio and results.

Read the numbers.
Then trust your ears.

A louder file can seem clearer at first. Measure the level before you judge a cleanup pass, and compare the same passage at a similar listening volume.

Integrated LUFS
The overall loudness of your track, with very quiet blocks excluded by gating. Useful for comparing complete versions of the same song.
Short-term loudness
A moving 3-second view. Find where a chorus becomes louder than a verse, or where the level changes after an edit. The maximum is the loudest complete window.
Momentary loudness
A shorter 400 ms window that follows quick changes. A brief rise is a moment to inspect, not an automatic reason to add compression.
Sample peak, in dBFS
The highest level among the decoded audio samples. It does not include peaks between samples. Use a true-peak meter for a required dBTP reading.

Measurement references: ITU-R BS.1770 defines K-weighted gated programme loudness; EBU loudness guidance explains integrated, 3-second and 400 ms readings.

Choose your next check

Compare without the loudness bias

Match playback levels before deciding whether cleanup improved the sound.

Read the A/B guide →

Look closer at a sound

See frequency energy over time with our other free browser tool.

Open the spectrogram generator →

Cleanup or mastering?

Pick the next step by the problem you hear, rather than a loudness number alone.

Read the workflow guide →

LUFS meter FAQ

Is my audio uploaded to measure LUFS?

No. This tool reads and decodes your chosen file in your browser, then measures it on your device. It does not upload the file, send the measurements to an API, or save the audio in persistent browser storage. Clear the file or close the tab to discard the working data.

What is integrated LUFS?

Integrated LUFS estimates the perceived loudness across the track. K-weighting accounts for how different frequencies contribute to loudness. Absolute and relative gates leave out very quiet measurement blocks, so long silence does not simply drag the result down. A less negative number means a louder measurement.

What is the difference between LUFS and sample peak?

LUFS describes loudness over time. Sample peak is the highest decoded sample level, in dBFS. Two tracks can have the same peak but different loudness. This meter does not calculate true peak in dBTP, so use a dedicated true-peak meter when your delivery specification requires it.

Which audio files can I measure?

Choose one mono or stereo WAV or MP3, no larger than 100 MB and no longer than 10 minutes. FLAC, OGG, M4A and AAC also work when your browser supports their codec. Audio must be at least 0.4 seconds long; a short-term reading needs at least 3 seconds. Surround files are not supported.

Should every song be mastered to the same LUFS?

No. A LUFS number is a measurement, not a universal quality target. Consider the sound you want, audible distortion, dynamics, and the requirements of the person or service receiving your file. Turning up a damaged export can make its artifacts more obvious.

Why can another meter give a slightly different result?

This tool measures mono or stereo audio decoded at 48 kHz, using K-weighting, overlapping 400 ms blocks, an absolute -70 LUFS gate and a relative -10 LU gate. Compare the same complete file and channel layout. Decoder differences, resampling, meter settings and selected passages can affect the reading. Mono is measured as one channel, without dual-mono compensation.

Does this tool make my track louder or clean it?

No. It measures your file and leaves the audio unchanged. Sunofix cleanup is a separate workflow in the app. If you open the app from this page, the selected file and the measurements are not passed to it.

Still hearing artifacts?

If your track has metallic shimmer or harsh highs, compare a Sunofix cleanup pass with your original. The app opens separately; your selected audio stays here.

Explore Sunofix cleanup