Low-Pass Filter Online
Soften harsh hiss, sizzle, and over-bright high-end on any audio file — pick a cutoff from 16 down to 4 kHz and everything above it rolls off, right in your browser. No sign-up, and your file is never uploaded.
How to Apply a Low-Pass Filter
No account, no upload — three steps on your own device.
Drop Your Audio
MP3, WAV, M4A, FLAC, OGG, or AAC up to 200 MB. It decodes right in the browser and draws the waveform.
Pick a Cutoff
Tap 16, 12, 8, or 4 kHz. A lower cutoff cuts more high-end for a warmer or lo-fi sound.
Preview & Download
Hit Apply Low-Pass, listen to the result, and download it as an MP3 at the bitrate you choose — no queue, no watermark.
Why Notevibes Low-Pass Filter
A clean high-end roll-off — warmth without the mud.
Four Cutoff Presets
Pick 16, 12, 8, or 4 kHz with one tap. A clean biquad low-pass rolls off everything above the cutoff.
Preview Before You Save
Filter, listen to the result, then download — or change the cutoff and try again. Nothing renders to a file until you like it.
Never Uploaded
The filter runs entirely in your browser. Your file never leaves your device — there is nothing to delete because nothing was sent.
Any Audio Format
MP3, WAV, M4A, FLAC, OGG, and AAC up to 200 MB — anything your browser can decode will load.
MP3 Your Way
Download the warmer file as an MP3 at any bitrate from 64 to 320 kbps — no watermark, no ads, no attribution.
Free, Anywhere
No sign-up, no daily limits. Works on phones, tablets, and laptops in any modern browser.
Nothing to Upload, Nothing to Leak
The filter runs on your own device. Your file never touches a server — which is a stronger promise than any “we delete it later”.
No Upload
Processing runs on your device
No Account
Start filtering immediately
Works Offline
Once the page loads, no connection needed
When to Low-Pass
One tap for every “this is too harsh or hissy” moment.
Tame Harsh Hiss
Roll off tape hiss and high-frequency sizzle above the cutoff
Lo-Fi / Telephone Effect
Drop the cutoff low for a muffled, vintage-radio sound
Piercing Sibilance
Soften harsh, over-bright “S” sounds on voices
Over-Bright Mixes
Pull back a brittle master for a smoother, rounder tone
High-Freq Whine
Cut electrical whine and fan noise sitting up top
Prep Samples
Band-limit samples before resampling or layering
Take the Edge Off Harsh, Hissy Audio
Some audio is exhausting to listen to — tape hiss riding on top, a mix that’s brittle and sharp, sibilance that pierces on headphones. The usual advice is to install an audio workstation and learn what a filter slope is. This tool skips all of that: drop the file, tap a cutoff, listen, download. Most files process in about a second, because they never leave your device.
One cutoff decides how warm it gets
A low-pass filter passes the lows and rolls off the highs above a cutoff you choose. Keep it at 16 or 12 kHz to shave only hiss and harsh air, drop to 8 kHz for real warmth, or go all the way to 4 kHz for a muffled lo-fi or telephone effect. It’s the same low-pass that powers the Notevibes audio editor, running through your browser’s built-in audio engine.
Preview before you keep it
Roll off too much and everything goes dull, so it’s never a blind bet. Apply a cutoff and play the preview against the original — still harsh, go lower; too muffled, come back up. Only when it sounds smooth do you download.
Free, private, and instant
Because the processing happens on your device, there’s nothing for us to meter or store: no upload, no queue, no watermark, no sign-up, files up to 200 MB. Preview as many times as you like and download the moment it sounds smooth.
From warmth to full cleanup
To cut rumble at the bottom instead of hiss at the top, the high-pass filter is the mirror image of this tool. If the harshness is really just sharp “S” sounds, the de-esser targets them without dulling the rest, and the full audio equalizer shapes every band at once. For cuts, mixing, or AI cleanup on top of filtering, open the file in the online audio editor.
Need to Do More Than Filter?
The full Notevibes editor trims, mixes, cleans up, and applies AI tools to your audio — then exports to MP3 or WAV.
Free to try · No credit card required
Related Audio Tools
More free AI audio tools from Notevibes — same engine, no sign-up.
High-Pass Filter
Cut low-frequency rumble below a chosen frequency.
Audio Compressor
Even out loud and quiet parts with dynamics compression.
Audio Normalizer
Boost audio to peak volume without clipping.
Stereo Widener
Widen the stereo image for a bigger sound.
Spectral Editor
Erase a cough, hum, or click by drawing on a spectrogram.
Online Audio Editor
Multi-track browser editor with every tool built in.
Low-Pass Filter FAQ
How does the low-pass filter work?
It applies a biquad low-pass filter at your chosen cutoff frequency — every frequency above the cutoff (16, 12, 8, or 4 kHz) is rolled off smoothly, while everything below passes through untouched. The result is warmer, smoother audio with the harsh high-end removed.
What does the cutoff frequency control?
The cutoff sets where the filter starts attenuating. A high cutoff like 16 kHz only trims the very top air and hiss. A low cutoff like 4 kHz removes most treble for a muffled, lo-fi or telephone sound. 8 kHz is a balanced default that tames hiss without dulling the audio.
Will it make my audio sound muffled?
It depends on the cutoff. 16 and 12 kHz are subtle and mostly remove hiss and harshness. 8 kHz adds noticeable warmth. 4 kHz is intentionally muffled — great for lo-fi and telephone effects, but use a higher cutoff if you just want to clean up hiss.
Is my audio file uploaded to a server?
No. The low-pass filter runs entirely in your browser using the Web Audio API. Your file never leaves your device — nothing is uploaded, stored, or analyzed.
What format is the download?
The filtered file downloads as an MP3, and you pick the bitrate — from 64 up to 320 kbps, with 192 kbps as the default. It plays everywhere: phones, editing software, streaming uploads.
Does it work on mobile?
Yes — Chrome, Firefox, Safari, and Edge on both desktop and mobile. Longer files render faster on a laptop simply because the processor is faster, but the tool is the same.