How to choose a car diagnostic scanner

Updated November 5, 2026

A diagnostic scanner plugs into your car's OBD2 port (on most cars since 1996, usually under the dashboard) and reads what the car's computers report. The right one depends on whether you just want to know why the check-engine light is on, or you do your own repairs and maintenance.

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Three levels of scanner

Basic code readers read and clear engine trouble codes and show live engine data. They suit drivers who want to understand a warning light before visiting a mechanic.

DIY scan tools add other systems, such as ABS, airbags and transmission, plus service resets like oil life, brake pads and battery registration. They suit people who do their own maintenance.

Professional and bidirectional tablets can also command parts to run (active tests), and some do coding and programming. They suit repair shops and serious enthusiasts.

Check compatibility first

Coverage varies by make, model, year and which system you need. Before buying, check the retailer's compatibility list or vehicle lookup for your exact car and the specific function you want.

Be wary of any scanner described as working on every car for every function. Coverage is never universal.

Updates and ongoing costs

Many mid-range and professional scanners include software updates for a set period, then charge a yearly fee. Check how long updates are included and what renewal costs.

Wireless (Bluetooth) scanners use a phone app. Tablet-style tools have their own screen, which is easier in a garage.

Quick checklist

Does it cover your car's make, model and year?
Does it support the systems and service functions you need?
How long are software updates included, and what do they cost after?
Do you need bidirectional control or coding, or just code reading?

Compare top picks

🔧 Not sure which scanner fits? Answer 3 quick questions and we'll suggest one. Shopping sales? Black Friday scanner deals.

Common trouble codes

Products to compare

In-stock products from retailers we partner with, grouped by price. Prices come from each retailer's product feed and can change, so confirm the price and vehicle compatibility on the retailer's site before you buy.

Affiliate links: COMPZA may earn a commission from qualifying purchases at no extra cost to you. AUTELOnline prices updated Nov 15, 5:03 AM EST · LAUNCH X431 Online prices updated Nov 15, 4:03 AM EST.

Where to shop

These links open search results at retailers we partner with. The retailer controls listings, prices and availability, so check them before you buy.

OBD2 code readers on eBay Bluetooth OBD2 scanners on eBay Bidirectional scan tools on eBay Battery testers on eBay Dash cams on eBay Portable jump starters on eBay OBD2 scanners at Walmart

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