# High-Pass Filter Audio
Apply a high-pass (low-cut) filter to audio in your browser — set a cutoff frequency to strip rumble, hum, and handling noise.
## Run it
- **CLI:** `gizza tool audio-highpass-filter 'url=https://example.com/input' 'cutoff=80' 'rolloff=12' 'format=mp3'`
- **Web:** https://gizza.ai/tools/audio-highpass-filter/
- **Agents:** machine-readable descriptor (parameters JSON Schema) at https://gizza.ai/tools/audio-highpass-filter/tool.json
## Inputs
- `file` — Audio _(file; accept: audio/*)_
- `cutoff` — Cutoff frequency (Hz) _(field)_
- `rolloff` — Rolloff (steepness) _(field)_
- `format` — Output format _(field)_
## Output
- Filtered audio (audio)
## Query parameters
Open the tool pre-filled and auto-run via URL:
- `cutoff` — Cutoff frequency (Hz)
- `rolloff` — Rolloff (steepness)
- `format` — Output format
- `url` — fetch the input file from a public URL (CORS-permitting)
Example: `https://gizza.ai/tools/audio-highpass-filter/?url=https://example.com/input&cutoff=80&rolloff=12&format=mp3`
---
## About this tool
**High-Pass Filter Audio** removes low-frequency content from a recording. A
high-pass filter (also called a *low-cut*) lets everything **above** a chosen
cutoff frequency pass through while attenuating everything below it — so rumble,
mains hum, HVAC drone, table thumps, plosives, and mic handling noise fall away
while speech and most instruments stay intact. Pick an audio file, set the cutoff
and how steeply it rolls off, choose an output format, and download the result.
Everything runs locally in your browser with a WebAssembly build of ffmpeg:
**your audio is never uploaded to a server.**
It only reduces low-frequency energy. Broadband hiss, mid/high noise, or one-off
sounds (a cough, a door slam) need a different tool — try the denoiser for steady
hiss/hum across the whole spectrum.
### Controls
- **Cutoff frequency (Hz)** — the corner frequency. Everything below it is cut,
everything above passes. **80 Hz** is the standard rumble cut that clears
low-end junk without thinning a voice; bump it to **100–120 Hz** for stubborn
hum, or higher to thin the low end on purpose. Range **10–2000 Hz**, default
**80**.
- **Rolloff (steepness)** — how sharply the filter cuts below the cutoff, in
dB/octave. **6** is the gentlest and most transparent, **12** (default) is the
natural choice for voice, **24** tightens the low end more, and **48** is a
steep brick-wall cut that can start to thin the sound. Gentler slopes sound more
natural; steeper slopes clear more low-end but can make voices sound thin.
- **Output format** — mp3 (192 kbps, default), wav, ogg, flac, or m4a.
### Worked example
Upload a spoken-word recording `interview.wav` with a constant air-conditioner
rumble, set **cutoff 100**, **rolloff 24 dB/oct**, and choose **wav**. The tool
runs `highpass=f=100:p=2,highpass=f=100:p=2` and returns
`interview-highpass.wav` — the same speech with the low drone gone. Want a smaller
file for the web? Switch the format to **mp3** and you get
`interview-highpass.mp3` at 192 kbps instead.
## FAQ
What is a high-pass filter, and when should I use one?
A high-pass filter passes frequencies **above** a set cutoff and attenuates those
**below** it — the opposite of a low-pass. Reach for it whenever a recording has
low-frequency junk you want gone: room rumble, air-conditioner or traffic drone,
50/60 Hz mains hum, desk thumps, footsteps, or the boominess of a close-mic'd
voice. It's the single most common first move when cleaning up voice, podcast, and
field audio.
What cutoff frequency should I pick?
Start at **80 Hz** — that clears most rumble without touching a voice, which lives
well above it. If low hum or drone remains, raise the cutoff in 10 Hz steps toward
**100–120 Hz**. For overhead/cymbal or bright-instrument tracks, a cutoff around
**120 Hz** trims rumble without dulling the tone. Keep it low (below ~120 Hz) on
material with real bass — a kick drum, bass guitar, or full music mix — so you
don't hollow out the low end you want to keep.
What does the rolloff / steepness setting do?
Rolloff is how sharply the filter attenuates frequencies below the cutoff, in
dB per octave. **6 dB/oct** is a gentle 1-pole slope that's very transparent;
**12 dB/oct** (the default) is a natural-sounding 2-pole slope good for voice;
**24** and **48 dB/oct** cascade more stages for a tighter, steeper cut. Steeper
slopes remove more low-end right below the cutoff but can start to sound thin or
unnatural — gentle slopes are safer on music, steeper ones are handy for aggressive
rumble control on speech.
Will this remove hiss or background chatter?
No. A high-pass only touches **low** frequencies. Steady broadband hiss (tape
hiss, mic self-noise) and mid/high noise pass straight through, and it can't
remove one-off events like coughs, clicks, or speech in the background. For steady
hiss/hum across the whole spectrum, use a spectral denoiser instead; this tool is
specifically for low-frequency rumble, hum, and handling noise.
Is my audio uploaded anywhere? What are the limits?
No. Processing happens entirely in your browser via a WebAssembly ffmpeg build —
the file never leaves your device. Practical limits: input up to about **10 MB**,
output up to about **10 MB**. Input can be any common audio format (mp3, wav, m4a,
ogg, flac); output is mp3, wav, ogg, flac, or m4a. Very long or high-bitrate files
may hit the size cap — trim or compress first.
## Related tools
- [Reduce Audio Background Noise](https://gizza.ai/tools/audio-noise-reduce/): Remove steady background hiss and hum from an audio file right in your browser — pick a strength, choose a denoiser, download. Runs locally, nothing is uploaded, free.
- [Compress an Audio File](https://gizza.ai/tools/audio-compress/): Shrink MP3, WAV, M4A or any audio file right in your browser — pick a target bitrate (96 kbps default) and format. Nothing is uploaded, free.
- [Convert an Audio File](https://gizza.ai/tools/audio-convert/): Convert any audio file to MP3, WAV, OGG, FLAC or M4A right in your browser — pick a bitrate for lossy formats. Runs locally, nothing is uploaded, free.
- [Add Effects to an Audio File](https://gizza.ai/tools/audio-effects-rack/): Add reverb, echo, chorus, tremolo and compression to audio in your browser — chain effects in one pass and download MP3, WAV or more. No upload.
- [Equalize an Audio File](https://gizza.ai/tools/audio-eq/): Equalize any audio file right in your browser — boost or cut bass, mid and treble in dB, then save as MP3, WAV and more. Nothing is uploaded, free.