BuzzOff listens for high-frequency tones used as mosquito repellents, "teen deterrents," or other annoying sound devices and alerts you when one is detected.
NOTE : BuzzOff does not record or store any audio. It only analyzes the live frequency spectrum in real time, entirely within your browser. No audio or data ever leaves your device.
Modes
- Annoy — Scans 14 .. 20 kHz, the broad range used by deterrent devices
- Mosquito — Focused on 16 .. 18.5 kHz, the classic "mosquito tone"
- Custom — Set your own frequency range
Alerts
- Notify — Sends a browser notification when a tone is detected. Useful when running in a background tab
- Beep — Plays a short audible beep tone (880 Hz, a pleasant A5 note) when detection starts
- Tab title — Changes the browser tab title to "⚠ DETECTED" so you can spot it at a glance without looking at the page. On by default
- Flash — Briefly flashes the screen red on detection
Sensitivity
Filter white noise
Spectrum detail
Note on Background tabs and Mobile
Every browser is a bit different. Phones are different to computers for a lot of reasons, and the people who make them use a lot of tricks to not use up your battery on stuff you're not using right now.
Browsers throttle background tabs to save resources. When BuzzOff is not the active tab, detection may be delayed or missed. For best accuracy, keep the BuzzOff window visible on screen — even in a
small window or a second monitor. This page/app will work best in a real computer, but it has been built to work ok on a phone too.
But if the page isn't on your screen it might not keep working properly for you. Sorry, I don't make the phone.
How it works
BuzzOff uses your computer's microphone to capture audio, then analyzes the frequency spectrum in real time looking for energy in the target band. It can only hear what your microphone can hear — so physical distance, walls, and your hardware's frequency response all affect results.
If your computer has more than one microphone or audio input (e.g. built-in mic, USB interface, headset), you need to select the right one in your system sound settings — BuzzOff uses whichever input your system has set as the default. It might even be using your headphones, the page can't know that.
Why and How I wrote this
Some jokers at school think it's hilarious to play the high-pitched "mosquito" tones to annoy the other kids in
class with pure plausible deniability. The teacher can't hear the tone, so nobody will ever know or prove anything,
right? Well maybe not, until now.
For those wondering, I'm an old-school engineer which means I have written my share of FFTs and DCTs by hand,
in languages and for platforms nobody cares about any more. For this app I just spent a nice free morning with
an AI agent which let me build it in straight no-dependency javascript. It's small, simple, and not quite
vibe-coded, but pretty close. And if it helps either of my kids find out which mouth breather is playing that
stupid annoying sound then it's been worth it.
The code and app are released free into the world under MIT license meaning you can go forth and use it
to find annoying sounds wherever they lurk. Go get 'em.
Dedicated to my kids - Love you <3
Installing as an app
BuzzOff can be added to your home screen or desktop so it opens like a regular app. That means you can install it once
and then use it even if you don't have internet access:
- iPhone/iPad: tap the Share button in Safari, then Add to Home Screen.
- Android (Chrome): tap the three-dot menu, then Add to Home Screen or Install app.
- Chromebook / Chrome desktop: look for the install icon in the address bar, or use the three-dot menu → Install BuzzOff.
