Your car has a problem?
Get an AI diagnosis right now — free.
Describe the symptoms, paste the fault codes or just photograph the dashboard. Diagnost tells you what it means, how serious it is and what to check first — like an experienced mechanic, in seconds.
How it works
Tell us what is wrong
Type the symptoms in your own words, paste OBD2 codes like P0301, or upload a photo of the warning lights or a scanner screen. Enter the VIN and the make, model and year are filled in for you.
AI analyses it
The model is trained on automotive diagnostics: it weighs your symptoms, car model and codes against known failure patterns.
Get a clear answer
What it means, how serious it is, whether you can keep driving, the likely causes from most to least common — and what to check first. The conversation is saved: you can come back and add details.
Four ways to diagnose
By symptoms
"Vibrates when braking from highway speed" — often that's enough for a solid first diagnosis and a check plan.
By fault codes
Have codes from any scanner or app? Paste them — you'll get plain-language explanations and the real-world causes, not just the standard definition.
By photo
Photograph the dashboard warning lights or the scanner screen. The AI reads it and explains what your car is trying to say.
Straight from the car
Have an ELM327 adapter over USB or Bluetooth LE? The site reads the fault codes itself and identifies your car by VIN — right in your browser, nothing to install.
Need to go deeper? There is a full program
Diagnost for Windows and macOS talks to every control unit in the car, not just the engine: scans ABS, airbags, transmission and body electronics on any make with a CAN bus, fault memory with plain-language explanations, live sensors, emissions readiness, the Toyota and Lexus hybrid battery, automatic VIN detection. For BMW with a cable — dealer-level depth: coding of hidden functions, service history, per-module mileage.
Frequently asked questions
Is the online diagnosis really free?
Yes. Five free AI diagnoses with no registration at all, plus ten more once you sign in with Google. The limits exist only to keep the service fast for everyone. Your conversations are kept in your browser for 30 days — you can return to an earlier case through “My conversations”.
How accurate is an AI car diagnosis?
It gives you the most likely causes ranked by real-world frequency and a sensible check order — the same first step a good mechanic would take. It does not replace physical inspection: use it to understand the problem and avoid paying for guesswork.
Can I keep driving with the check engine light on?
It depends on the cause. A steady light with no symptoms usually allows careful driving; a flashing light means active misfires that can destroy the catalytic converter — stop soon. Run the diagnosis and it will tell you for your specific case.
Which cars are supported?
Symptom, code and photo diagnosis works for every make and model. The program for Windows and macOS additionally polls every control unit in the car — ABS, airbags, transmission, body electronics — on any make with a CAN bus (roughly 2008 and newer), shows live sensors and checks the Toyota and Lexus hybrid battery. Dealer-level depth for BMW — coding, service intervals, per-module mileage — needs a K+DCAN or ENET cable and the Windows version.
Do I need to install anything?
No. Everything works in the browser — even reading codes from the car, if you have an ELM327 adapter over USB or Bluetooth LE. The program for Windows and macOS is optional: it reads every control unit, not just the engine, and it also works with classic Bluetooth and WiFi adapters.