Some recordings (especially from certain audio interfaces or cables) sit slightly off-center. This detects that offset and re-centers the waveform around zero.
A DC offset means a recording’s waveform is not centred on zero — it sits slightly above or below. It cannot be heard directly, but it wastes headroom, makes editing click, shifts loudness readings and can overload compressors and limiters.
This tool measures the offset in percent of full scale and removes it by subtracting each channel’s mean, with an option for a 10 Hz high-pass that also removes slow drift from cheap sound cards.
The mean of all samples in each channel is the DC component. Subtracting it re-centres the waveform exactly. If the offset changes over time (drift), a 2nd-order Butterworth high-pass at 10 Hz — far below audibility — removes anything slower. The result card reports the offset before and after to four decimals.
Start with a clean, centred signal.
Prevent clicks at cuts.
Fix offset from old converters.
Fix drift from poor hardware.
| Method | Mean subtraction per channel (+ optional 10 Hz high-pass) |
|---|---|
| Reported precision | 0.0001% of full scale |
A constant (0 Hz) component added to the audio.
Not directly, but it causes clicks and wasted headroom.
It's usually a hardware quirk — a cheap audio interface, a bad cable, or certain microphones can introduce a small constant voltage bias into the recording.
It wastes headroom (you can't get as loud before clipping), can cause audible clicks at edit points, and confuses some level meters.
This tool runs entirely in your browser using the Web Audio API. Nothing is uploaded, stored or shared — there is no server to send your file to, so it works offline once the page has loaded.
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