Inside the app
Diagnose. Decide. Drive on.
Six screens, one workflow — from the first odd noise to the right shop in your area.
What’s it doing?
Last diagnosis
Belt squeal · Moderate
01 / Diagnose
Two ways in: record the noise or scan the problem.
Live run
See it in action
A 60-second walkthrough — record the noise, read the diagnosis, find the shop.
What it does
A mechanic’s ear, in your pocket
Real diagnostics, plain-English verdicts — no jargon, no upsell.
Diagnose by Sound
Hold up your phone and record the noise. Knock isolates the signal and matches it to belt squeal, rod knock, brake grind, and more — with a confidence score.
Diagnose by Sight
Can’t hear it but can see it? Scan a leak, a worn pad, or a dash warning light and get the same structured read on what’s wrong.
Severity at a Glance
Every result lands on a diagnosis card: a severity dial, urgency chip, and a plain-English verdict so you know if it’s a drive-home or a tow.
Real Cost Ranges
Mono cost readouts give you a repair estimate before the shop does — so you walk in informed and never get talked into a part you don’t need.
DIY vs. Shop Verdict
A green-or-red call on every fix, plus the exact parts you’d need. Save the easy jobs for the driveway, send the hard ones to a pro.
Find a Shop That Fits
Tap straight from a diagnosis into rated shops nearby — filter by specialty, price, and hours, then call or request an estimate in one tap.
The diagnostics get smarter
Today Knock runs on tuned sound and vision models. Next: it plugs into your car’s own data and learns your specific engine over time.
Learns Your Engine
Knock builds a baseline of how your specific car sounds, so it flags new noises the day they appear — not weeks later.
PlannedOBD-II Live Data
Pair to your car’s diagnostic port and fuse fault codes with the sound and photo read for a single, confident diagnosis.
PlannedPredictive Maintenance
Mileage- and pattern-based alerts predict the brake, belt, or fluid job before it strands you on the shoulder.
PlannedShareable Repair Brief
AI drafts a clean summary — symptom, likely cause, parts, fair price — you can hand straight to any mechanic.
PlannedFollow the build
Watch Knock get built
Knock is app #97 in the 100 Apps 100 Hours sprint. Every screen recorded, every fix shipped on camera — follow along for daily drops, teardown clips, and early looks.
Hearing a noise you can’t place?
Join the waitlist and be first to point Knock at it when we launch.
Stop guessing. Start diagnosing.
Join the waitlist for early access, launch updates, and the first diagnoses straight to your inbox.
No spam. Unsubscribe any time. Prefer to talk? Grab a 30-minute slot.