Stop Nail Biting with AI
Stop Biting uses your webcam and on-device AI to detect nail biting in real time. The moment your hand moves toward your mouth, an audible alarm fires — catching the automatic episodes you never notice. All detection runs locally via MediaPipe and WebAssembly: no camera data ever leaves your device.
Try the detector right now
Run the real nail biting detector on your own camera for 60 seconds — no account, no signup. The AI models download once (about 20 MB) and then everything runs on your device: open your browser's network panel and you'll see zero requests while it is watching. Nothing is uploaded and nothing is saved.
How it works
Open the app in your browser (or the macOS/Windows desktop app), grant camera access, and work normally. The AI tracks 21 hand landmarks and your face mesh at 30fps, entirely on-device. When it detects your hand approaching your mouth, the alarm fires within a second — the external awareness signal that Habit Reversal Training identifies as its most critical component. Each detection is logged locally so you can see your real biting frequency and triggers. Read more at how it works.
Pricing
Simple, honest pricing. Start with a 3-day free trial — no credit card required. Monthly: $2.99/month. Yearly: $29.00/year — just $2.42/month, saving 19%. Both plans include unlimited AI detection, streak and habit tracking, full incident history, and all alert types. Secure payment via Paddle, cancel anytime. See pricing details.
Frequently asked questions
Why do people bite their nails?
Nail biting (onychophagia) is a body-focused repetitive behaviour affecting up to 30% of adults. Common triggers are stress, anxiety, boredom, and deep focus. The habit usually starts in childhood and becomes automatic — happening without conscious awareness. Genetic predisposition, perfectionism, and OCD-spectrum tendencies are also linked.
What are the best remedies to stop nail biting?
The evidence-based options are habit reversal training (the strongest by some margin), bitter-taste polishes like Mavala Stop, real-time awareness tools such as AI detection, competing response training, and stress reduction. Most people do best combining an awareness method with a competing response rather than relying on any single remedy.
What is habit reversal training for nail biting?
Habit reversal training (HRT) is a cognitive-behavioural method with three parts: awareness training — learning to notice every time you bite; a competing response — an incompatible action like clenching a fist or pressing your palms flat; and social support. In the original Azrin and Nunn clinical trial, participants who practised it consistently achieved a near-complete reduction in biting.
Is nail biting harmful?
Yes. Chronic nail biting causes dental damage including chipped teeth and jaw strain, nail fold infections, transfer of pathogens from fingers to mouth, and permanent nail deformity in severe cases. The visible damage also drives shame and social anxiety, which increases biting — a self-reinforcing cycle.
Does Stop Biting send my camera feed to the internet?
No. Detection uses MediaPipe — Google's WebAssembly vision framework — running entirely on your device. Your camera feed is never uploaded, streamed, or stored anywhere outside it. There are zero network requests during detection: you can disconnect from the internet and the app works identically.
How long does it take to stop biting your nails?
Most people notice more biting in week one, because they are finally catching episodes they used to miss. Frequency typically starts dropping meaningfully between weeks two and four, and the competing response starts feeling natural around weeks six to eight. Habit-formation research suggests a median of roughly two months for a new response to become automatic.