Keeping one of the best OBD-II scanners in your car is a great tool for saving you money on unexpected repairs. Because the last thing you need is to see the check engine light pop up, and have to pay a mechanic to diagnose and fix a problem that would have taken a few minutes to do yourself.
On-board diagnostic (OBD) scanners can plug directly into your car's access port, right by the driver's seat, and give you a glimpse into your car's computer system. It can tell you if that light was caused by something simple you can fix yourself, or the kind of thing that is going to cost thousands of dollars for a professional to handle.
OBD-II scanners, sometimes written as OBD2 scanners, or EOBD scanners in Europe, also let you see what's going on with your car's engine, transmission and other critical systems. That's information that normally only your mechanic has access to.
Whether you're taking your car in for a routine inspection, or for some sort og major repair, it always helps to have this vital information to hand. At the very least it's stop you getting tricked into paying for unnecessary repairs.
In fact, once you know everything that's going on with your wheels, you can end up doing a lot of the smaller stuff yourself. That makes the best OBD-II scanners — which range in price from $25 to $200 — pay for themselves.
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We've tried out and tested more than a dozen OBD-II scanners, and we've rated them based on features, size, warranty, setup, ease of use and — above all — value. The best OBD-II scanners can diagnose thousands of automotive problems.
OBD-II/EOBD scanners work on almost all passenger vehicles sold in the United States since 1996, in Canada since 1998, in the European Union since 2004, and in Australia, Mexico and New Zealand since 2006. (Here's how to find your car's OBD-II port on North American cars, and here's how to find your OBD-II/EOBD port worldwide.)
Not all the best OBD-II scanners are created equal. There are two general types of devices.
Handheld OBD-II scanners come with their own screen and cable to plug into the car's OBD port.
Wireless OBD2II scanners plug into the port, but then connect via Bluetooth to a smartphone or tablet to display their findings.
Whichever type you choose, there are several high-performance OBD-II scanners that cost less than $200. A couple are less than $30. One of the best OBD-II scanners is no longer an unaffordable luxury, but something you need to have in your car.
What are the best OBD-II scanners?
The best OBD-II scanner we used and tested is the Innova CarScan Inspector 6100p. It has a color display, delivers a ton of useful data, shuts off the oil-change light and can run your car through a pre-inspection test. Unlike most scanners, it has both a handheld screen and the ability to connect to an app on your phone via Bluetooth.
The Innova provides code definitions to help you easily identify car problems and the Repair Solutions2 app helps you get verified fixes and will give you the exact parts you need, recall info and more.
The Topdon ArtiDiag500 is our second Editor's Choice. It has an unusual horizontal screen, has a full complement of functions and abilities, and is one of the few scanners that can connect to Wi-Fi.
The BlueDriver Pro Scan Tool is our top pick among Bluetooth-only scanners. It's a thick stubby plug that you can leave connected to your OBD-II port, but the app is elegant and well designed.
If you have a GM, Ford, Chrysler or Toyota car from the '80s or early '90s in your driveway, Bosch's OBD 1300 might be a godsend. It comes with specialized cables to connect to those pre-1996 "OBD-I" models.
See all of our picks for the best OBD-II scanners below.
The best OBD-II scanners you can buy today
The Innova 6100P is the kind of OBD-II scanner that can make any amateur mechanic feel like a professional. This crossover device can function as both a handheld unit, while also connecting to the Innova app, and offering up a great variety of diagnostic abilities.
The $140 Innova 6100P has all the features you would want from an amateur mechanic's OBD-II scanner. Its 2.8-inch color screen displays everything from live data to fault codes to a pre-inspection I/M readiness check.
Innova 6100P can connect via Bluetooth to the Innova RepairSolutions 2 app on an iPhone or Android phone. The app adds maintenance schedules, service bulletins and predictive-failure warnings. The best part, however, is its ability to suggest repairs and parts your car might need.
Read our full Innova 6100P review.
The Topdon ArtiDiag500 straddles the line between amateur and professional users with a large color touchscreen, Wi-Fi and an automotive health report.
It looks like a rugged portable gaming console, feels like a brick and has a 47-inch cable that won't quite reach the engine bay (and won't fit into the carrying case when attached to the unit).
Despite that, the Topdon ArtiDiag500 is one of the most capable consumer-grade OBD-II scanners we've seen. It can monitor the brakes, airbags and battery, run an I/M pre-inspection test and also display and graph live car data. The Android-based unit has its own rechargeable battery and can update its own software, two things you don't often see on handheld scanners.
It may be big and heavy, but the Topdon ArtiDiag500 might be the best $170 a car owner can spend on an OBD-II diagnostic scanner.
Read our full Topdon ArtiDiag500 review.
The BlueDriver Pro Scan Tool is one of the most thorough Bluetooth-based automotive scanners, combining access to both basic and manufacturer-specific faulty codes and providing advice on how to fix problems.
The physical device is rather large, but that makes it easy to plug it into or yank out of an OBD-II port. An LED on the device lets you know whether it's in operation or in fault mode.
The BlueDriver mobile app is user-friendly and well laid-out, displaying data in automotive-style gauges and letting you export data to a spreadsheet. There's an I/M readiness test called a Smog Check, diagnostic tests for anti-lock brakes and engine timing, and Mode 6 in-depth diagnostic testing, although the amount of data collection may depend on your car's model and year.
Read our full BlueDriver Pro Scan Tool review.
The Bosch OBD 1300 diagnostic scanner stands out by including cables to connect with pre-1996 Chrysler, Ford, GM and Toyota cars. It can get heavy once the 6-foot extension cable is attached, but the OBD 1300's small size hides its powerful range of abilities.
Unlike many handheld diagnostic scanners, the Bosch OBD 1300 doesn't get power from your car's OBD-II port. Instead, it uses AA batteries or your car's cigarette lighter to power its large color screen, which shows graphing data clearly.
The scanner's database holds details on 26 million repair suggestions. It can check the anti-lock brakes and air bags on most cars released from 1996 to 2013, monitor the charging system and battery and run a pre-inspection emissions test. You'll need to get the instruction manual from Bosch's website.
With a list price of nearly $200, the Bosch OBD 1300 may seem expensive until you see how many cars it can work with. It's the diagnostic scanner to get if you have an '80s or early-'90s car.
Read our full Bosch OBD 1300 review.
Foxwell's NT614 Elite diagnostic scanner squeezes a large color screen into a small, rugged horizontal case. It's powerful and can probe many car problems, but we wish it had a touchscreen and could run on battery power.
Like the similar-looking but bulkier Topdon ArtiDiag500, the Foxwell NT614 is aimed at professional mechanics as well as car owners. It can graph data, cancel the oil-change light, and monitor the charging system, air bags, brakes and transmission.
Two unique features stand out. Like a gaming keyboard, the Topdon ArtiDiag500 has programmable keys that can be set up to do different things with different makes of cars. It also has a microSD card slot for data storage. It may be the OBD-II scanner to have if you do a lot of work on cars from different manufacturers.
Read our full Foxwell NT614 Elite review.
The ThinkCar ThinkDiag TKD01 is among the largest Bluetooth-based OBD-II automotive diagnostic scanners. It can show you extended fault codes or turn off the oil-change light, but be wary of the annual app-subscription plan.
At more than three inches across, the ThinkDiag is so big it won't fit into some OBD-II ports. You may need an extension cable to connect to your car's systems. On the upside, the rugged oval-shaped unit is practically indestructible.
The ThinkDiag app offers profiles for more than 100 automakers, letting you dig deep into manufacturer-specific codes. You get one profile for free for the first year, but after that each profile is $40 per year (and even more for Teslas). If you have multiple cars of different makes, you'll pay for each profile.
The app can turn off the oil-change light, check tire pressure, airbags and brakes, and predict which systems will go south soon. However, it doesn't tell you which replacement parts or repairs might be needed.
Read our full ThinkCar ThinkDiag TKD01 review.
Ancel's BD310 is just as good as a handheld scanner with a screen as it is when connected to a phone or tablet via Bluetooth. It can also augment the car's cockpit with a supplemental display of key engine parameters. Think of it as freedom-of-scanning choice.
Small and lightweight, the BD310 can live in your car's glove box. Its icon-based, 2.0-inch color display is a little skimpy but easy to figure out, regardless of whether you want an I/M inspection-readiness test or performance details, like coolant temperature, engine timing and engine speed. They can be shown as numbers or graphs.
It has a 56-inch cable that makes it just as good for hanging over the hood looking for an engine problem as monitoring the engine while driving. On the other hand, the BD310's rudimentary four-key interface can make navigation awkward. There's also a mode button on the side for selecting Bluetooth and cable operation.
Read our full Ancel BD310 review.
Unlike most OBD-II scanners, Autel's AutoLink AL539 can check electrical connections with a built-in multimeter to uncover electrical shorts or burned-out cables. The device's lithium-ion battery powers it for checking fuses, the alternator's voltage or the gas gauge. Just note that the multimeter doesn't work when the AL539 is connected as an OBD scanner.
The AL539 not only shows live data, like engine speed, coolant temperature and other items but also can run a comprehensive pre-inspection readiness test. It shows results as three lights for faults: red (permanent fault), yellow (temporary fault) or green (no faults).
Despite its soft rubber bumpers, the AL539 is fairly compact and light at 6.7 x 3.6 x 1.4 inches and 10.6 ounces. It has a unique pull-out leg so the device can stand on its own, as well as a generous 58-inch cable. Its bright, 2.8-inch color display has icons for major functions and an easy-to-follow, eight-key interface.
Read our full Autel AutoLink AL539 review.
Its large color screen, range of tasks, lifetime warranty and ease of use make the SeekOne SK860 a winner.
The price for this is a handheld scanner that can feel bulky and heavy. Its soft rubber bumpers and rugged design mean you don't have to baby the SK860, and it comes with a 58-inch cord and bright, 2.8-inch color display.
Its eight-button navigation scheme and icon-based interface are easier to use than budget scanners. The SK850 has a one-button I/M pre-inspection readiness check along with a green (no-fault codes), yellow (intermittent problems) and red (permanent-problem codes) LED scheme.
The SK860 does much more than typical handheld scanners and comes with a padded case, but its lifetime warranty makes it stand out from the crowd.
Read our full SeekOne SK860 review.
The EDiag YA-101 is small and light, and its inexpensive price belies its wide array of diagnostic functions that include a battery-test sequence and an I/M inspection-readiness test. It has a lifetime warranty that includes endless firmware updates.
What you won't get are the manufacturer-specific codes and routines available on OBD-II scanners that costs many times more than the EDiag YA-101. This scanner has a color screen and a fairly intuitive interface, but it doesn't graph data and can't turn off the oil-change light. Nor can it suggest repairs or replacement parts.
The EDiag YA-101's 32-inch cable isn't enough to reach the engine bay. If you want to get under the hood while the scanner is plugged in, you'll need an extension cable. Nonetheless, this is a great way to get started with using OBD-II devices, and you'll get a lot of bang for the buck with this cheap but reliable scanner.
Read our full EDiag YA-101 review.
How to choose the best OBD-II scanner for you
If you're looking for insights into how your vehicle is working or what's wrong under the hood, there's no better way than to plug in one of the best OBD-II scanners and read the results.
After all, it's how your car dealer or repair shop would figure out what's wrong with your car when you drive (or are towed) in. Why shouldn't you have the same information?
Not all the best OBD-II scanners are created equal. There are two general types of devices.
Handheld OBD-II scanners come with their own screen and cable to plug into the car's OBD port. Wireless OBD2II scanners plug into the port, but then connect via Bluetooth to a smartphone or tablet to display their findings.
Whichever type you choose, there are several high-performance OBD-II scanners that cost less than $200. A couple are less than $30. What's important to remember is that the best OBD-II scanners provide the right mix of size, weight and the ability to read your car's fault codes and live data. The most important criteria are:
- Easy setup. If it takes forever to set up the scanner, you probably won't use it to diagnose a problem early.
- Faults and explanations. The best OBD-II scanners not only tell you the faults your car has but also can explain the meaning so you can either fix it yourself or tell a mechanic.
- I/M Readiness check. A good scanner will run the major engine and emissions tests to see if you'll pass your state's inspection.
- Accuracy. A scanner is worthless if its results aren't accurate, because the only thing worse than no information is incorrect information.
- Size and weight. If the scanner is heavy and bulky, chances are it'll stay in your toolbox and not in the car to help you on the road.
- Live data. By tapping into the car's engine speed, timing and other parameters, the right scanner can help track down an intermittent problem.
- Graphs. Numbers are good, but a visual representation of it is much better, particularly if you're comparing before and after.
- Warranty. You expect your car to last at least eight or 10 years, so why shouldn't your OBD-II scanner? That said, the best offer a lifetime warranty that should outlast your ride.
There's a gas tank full of criteria used to determine which OBD scanner is the best one for you. The most important is whether you want one that connects with your phone or tablet's screen over Bluetooth or a handheld unit with its own display and cable.
Next, think about longevity and get one that includes lifetime warranty or software updates so the scanner will stay current with changing automotive tech.
Then, how about screen size for a handheld scanner? Get the biggest, brightest and easiest display to read that is icon based for easy changes. If you're clumsy, look at rugged scanners with rubber bumpers to absorb the shock of being dropped.
Look for extras that are included on some models, like an electrical multimeter, the ability to read a manufacturer's proprietary codes or export documents as Acrobat PDF files.
Finally, the price for these sophisticated devices is right on par with professional-level scanners that are available for under $100. That's barely an hour's labor for a qualified mechanic, making it a win-win purchase.
How we test OBD-II scanners
To test the best OBD2 scanners, I used my 2014 Audi A4 Allroad vehicle while it was in the garage or on the road over a period of several weeks. After connecting each scanner to my car's OBD-II port, I made sure they could report the car's vehicle identification number (VIN).
For the wireless scanners, I connected to my Apple iPad Pro, Microsoft Surface or Samsung Galaxy S9+ phone via a Bluetooth or Wi-Fi connection. The handheld scanners only needed to be plugged into the OBD-II port, which provides power.
Next, I measured the cord's length on the handheld scanners and the wireless range on the others. With the car running, I monitored the engine and other vital systems, and then disconnected the engine's oil temperature sensor.
Finally, I checked the details provided by the scanner, fixed the problem, turned off the check engine light and erased the error code.
Then I hit the road to see if the scanner could display operating data such as engine speed, timing and coolant temperature. I paid attention to whether the device reported the data as numbers, graphs or auto-style gauges.
Regardless of which OBD-II scanner you use, you'll need to crack its code. All fault codes have four numbers and a letter prefix:
- Powertrain (P)
- Body (B)
- Chassis (C)
- Undefined (U)
Of the roughly 5,000 diagnostic fault codes available, some are generic and apply to all cars, like air temperature and throttle position. For these, the numeric section starts with a 0. Others are specific to individual carmakers and represent either a special piece of hardware or a more in-depth analysis of the problem. These start with a 1.
For instance, if you get a P0098 code, chances are there's something wrong with the engine's intake air temperature sensor. By contrast, a Ford that displays a P1112 specialty fault code means that the intake air temperature sensor is reporting values intermittently and should be replaced.