Low-Pass Filter Online
Remove high-frequency hiss, harshness, and air above a cutoff in your browser. Pick from 16 to 4 kHz — instantly get warmer, smoother MP3 audio, no sign-up, no upload.
Filter Audio in 3 Steps
No knobs, no listening tests. Drop, pick, download.
Upload Your Audio
Drag and drop an MP3, WAV, or other audio file. Up to 200 MB.
Pick a Cutoff
Tap 16, 12, 8, or 4 kHz. Lower cutoffs cut more high-end for a warmer or lo-fi sound.
Apply & Download
Hit Apply Low-Pass. A 192 kbps MP3 with the high-end rolled off is saved to your device.
Why Notevibes Low-Pass Filter
Clean cutoff, warmer tone.
4 Cutoff Presets
Pick 16, 12, 8, or 4 kHz with one click. A clean biquad low-pass rolls off everything above the cutoff.
Instant Result
The filter is rendered through OfflineAudioContext in seconds. Drop, pick, download.
Privacy First
Audio is processed locally in your browser using the Web Audio API. Nothing is uploaded.
Any Audio Format
MP3, WAV, M4A, FLAC, OGG, AAC up to 200 MB. Anything your browser can decode loads.
Clean MP3 Output
192 kbps MP3 saved straight to your device — no watermark, no ads, no attribution.
Works on Mobile
Filter audio on your phone or tablet. iOS, Android, Chrome, Firefox, Safari, Edge.
Your Audio Stays on Your Device
Every file is processed locally in your browser using the Web Audio API. Nothing is uploaded, stored, or analyzed.
No Upload
File never leaves your device
No Account
Start filtering immediately
No Tracking
We never see your audio
When to Use a Low-Pass Filter
Most files process in under a second.
Tame harsh hiss
Roll off high-frequency hiss and tape noise above the cutoff
Lo-fi / telephone effect
Drop the cutoff low for a muffled, vintage radio sound
Reduce sibilance-heavy noise
Soften piercing 's' sounds and harsh high-end on voices
Warm up bright recordings
Pull back over-bright mixes for a smoother, rounder tone
Remove high-freq whine
Cut electrical whine and fan noise sitting up high
Prep samples
Band-limit samples before resampling or layering in a mix
Need Full Tone Shaping?
The Notevibes Audio Editor stacks low-pass filtering with EQ, bass boost, compression, limiter, and effects — process whole tracks in one pass.
Open Full Audio EditorConvert Any Audio Format
Free browser-based converters for every major audio format — no sign-up, no upload.
Related Audio Tools
More free browser audio tools from Notevibes — no sign-up, no upload.
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.
Frequently Asked Questions
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 the low-pass filter free?
Yes. Completely free with no sign-up, no watermark, and no limits. Max file size is 200 MB.
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 audio formats are supported?
MP3, WAV, M4A, FLAC, OGG, and AAC. Anything your browser can decode via the Web Audio API will load. The processed output is exported as a 192 kbps MP3.
Does it work on mobile?
Yes. It runs on Chrome, Firefox, Safari, and Edge on both desktop and mobile. Tap to upload, pick a cutoff, tap Apply Low-Pass.
Can I create audiobooks with Notevibes?
Yes. The AI audiobook generator turns your EPUB, Kindle, or PDF into a narrated audiobook with character detection, 550+ voices, and ACX-compliant volume normalization built in.