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Low-Pass Audio Filter Online

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Soften high-frequency content with a selectable low-pass cutoff. Apply a second-order Butterworth filter to each channel and compare the tonal change.

Set the upper tonal boundary

Lowering the cutoff removes more high-frequency content. Start high and move downward while listening for lost consonants, cymbals or brightness.

Expect a gradual roll-off

The cutoff is not a brick wall. A second-order filter progressively attenuates frequencies beyond the cutoff rather than deleting them completely.

Use it for tone shaping

A low-pass filter can make a track darker or reduce some high-frequency noise. It also affects wanted content in the same frequency range.

Respect the sampling limit

The usable cutoff is limited below half the sample rate. Frequencies above the recording’s representable range cannot be selected meaningfully.

Technical references: Web Audio API specification

Audio Low-Pass Filter FAQs

It can reduce high frequencies, but speech clarity may also change. It does not distinguish noise from wanted sound.
Use Audio High-Pass Filter for low-frequency attenuation.
Lowering the cutoff reduces high-frequency components that contribute to consonant clarity and brightness. Raise it until the voice remains intelligible. A low-pass filter changes all material above its cutoff; it cannot distinguish unwanted hiss from wanted detail at the same frequencies.
Audio Low-Pass Filter updates the effect during playback when you adjust a control. Use A/B to compare with the source. Render download creates a separate file using the current settings; moving a slider invalidates the previous download.

Related tools

Audio High-Pass Filter

Reduce frequencies below a chosen cutoff.

Audio Equalizer

Adjust bass, midrange and treble with a three-band equalizer.

Audio Noise Gate

Reduce quiet background sound using a threshold and smooth gain envelope.