Why we built a browser-based dog whistle
A free, no-sign-up ultrasonic tone generator that turns the speaker you already own into an adjustable dog whistle, built around honesty about what high-frequency sound can and cannot do.
Dog Whistle is a small web app that uses your browser's Web Audio API to play a clean sine wave at whatever pitch you choose, from a clearly audible 8 kHz up to an ultrasonic 22 kHz. There is no app to install, no account to create, and nothing to buy. You open the page, pick a frequency or a preset, and your phone or laptop speaker does the rest. Everything is generated on your device in real time, so the tone starts the instant you press play.
We added the parts that a plastic pocket whistle cannot give you: a frequency slider so you can find the pitch your dog responds to, presets for recall, nuisance barking, cats, and rodents, a pulse mode for grabbing attention outdoors, and a 1 kHz speaker self-test so you can confirm your audio is working even when the whistle itself is too high for you to hear.
Most people reach for a dog whistle in a single frustrated moment: a dog that bolts at the park, a neighbor's complaint about barking, a new puppy that needs a recall cue. The physical whistles sold online come in a fixed pitch you cannot change, and you have no way to tell whether the thing is even producing sound. We wanted a version you could try in ten seconds, tune to your own dog, and test honestly, without spending money to find out it does not suit your situation.
Just as important, we wanted to be straight about the limits. A whistle is an attention and training aid, not a remote control for behavior. It works when you pair the sound with something the dog cares about, a treat or praise or a recall, so the tone comes to mean something. On its own, a high pitch will not reliably stop barking or fix a habit, and small phone speakers often roll off before they reach true ultrasonic frequencies. We say all of that plainly on the tool itself because a product that overpromises just wastes your time.
Dog owners working on recall, people trying a humane way to interrupt nuisance barking, trainers experimenting with marker cues, and curious folks who just want to know whether their dog or cat reacts to ultrasound. Whoever you are, please use it gently: keep the volume moderate, keep sessions short and positive, never aim it to startle or punish, and stop if your animal looks anxious rather than curious. For real behavior or health concerns, a veterinarian or qualified trainer is the right call, not a web page.
Dog Whistle is one of a family of free, browser-based sound tools we build, alongside TestTones for speaker and hearing checks and Siren Generator for alert sounds. They all share the same idea: a focused audio tool that runs entirely in your browser, with no downloads and nothing to sign up for. If you want to understand the tool more deeply, the science of hearing page explains why dogs hear what we cannot, and the FAQ answers the questions we hear most.