Getting one of the best OBD2 scanners can not only be a lifesaver when your car's "check engine" light comes on but also can provide rare insight into the deeper recesses of the vehicle's engine, transmission and other vital components. By tapping into the car's control computer, an onboard diagnostics scanner can tell you the difference between a faulty $30 gas cap and a bad catalytic converter costing many times more.
With this knowledge, those who are handy can often do many of the repairs themselves. Those who are not so handy are no longer at the mercy of disreputable repair shops looking to inflate the bill as much as possible. After all, knowledge is power.
We've looked at dozens of OBD2 scanners and rated them based on features, size, warranty, setup, ease of use and – above all – value. These scanners can diagnose thousands of car problems, and they work on vehicles made since 1996. But all scanners are not created equal, with two general types of devices:
- Handheld OBD2 scanners come with their own screen and cable to plug into the car's OBD port.
- Wireless OBD2 scanners connect via Bluetooth to a phone or tablet.
The good news is that whichever approach you choose, there are several high-performance OBD2 scanners that cost less than $100. In other words, having one of these devices is no longer a luxury you can't afford, but something you need to have in your car. After all, the next time you break down, it would be nice to know the cause before someone starts repairing it.
What are the best OBD2 scanners?
Out of the dozens of OBD2 scanners we've tested, the best not only show what's going on under the hood but also can perform extra car maintenance tasks while having greater longevity. Three scanners stand head and shoulders above the rest by going beyond the expected with helpful extra technology.
Overall, the best OBD2 scanner right now is Ancel's BD310. It does double duty by providing a small but efficient cabled handheld scanner for nosing around under the hood that also can wirelessly receive OBD data to serve as an auxiliary gauge inside the cabin to display key engine parameters. It's also quite affordable.
Meanwhile, the Autel AutoLink AL539 adds something that few scanners have: a handy electrical multimeter tester and test leads for tracking down everything from a faulty cable to checking on whether a fuse has blown. As innovative and helpful as it is, however, you can't use the scanner and multimeter at the same time, and the device needs to be periodically recharged.
Finally, the Seekone SK860 is as close to a professional scanner as it gets these days for $62. Its large color screen, intuitive interface and battery test are complemented by a rugged design that should be able to stand up to abuse in the garage. It adds something the others lack: a lifetime warranty, which means that the SK860 could be the last scanner you'll ever need, regardless of how many miles you drive.
The best OBD2 scanners you can buy today
1. Ancel BD310
The best OBD2 that does double duty
Display/size: Color/2 inches | Bluetooth/handheld: Yes/yes | I/M Readiness test: Yes | Displays live data: Yes | Number of keys: 4 | Warranty: 3 years | Size: 5.1 x 2.4 x 0.6 inches | Weight: 5.4 ounces
The best OBD2 scanner overall, 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 measures 5.1 x 2.4 x 0.6 inches and weighs 5.4 ounces, meaning that it 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.
This ODB scanner quickly connected with my 2014 Audi Allroad and displayed a graph of the engine speed along with other parameters. Later, it found my introduced fault and was able to turn off the car's check engine light. The Ancel BD310 includes a three-year warranty and can do so much more than single-purpose scanners.
2. Autel AutoLink AL539
A smart OBD2 scanner pick for diagnosing electrical problems
Display/size: Color/2.8 inches | Bluetooth/handheld: Yes/no | I/M Readiness test: Yes | Displays live data: Yes | Number of keys: 8 | Warranty: 1 year | Size: 6.7 x 3.6 x 1.4 inches | Weight: 10.6 ounces
Autel's AutoLink AL539 is one of the best OBD2 scanners because it does something that most other OBD2 scanners can't: It can check electrical connections with a built-in multimeter to uncover pesky electrical shorts or burned-out cables. Just note that the multimeter is a stand-alone function that doesn't work when the AL539 is connected to the car as an OBD scanner.
The AL539 has connectors for the multimeter's included test cables for doing anything from checking continuity and current to voltage. The device's lithium-ion battery powers it for checking fuses, the alternator's voltage or the gas gauge. The AL539 not only shows live data, like engine speed, coolant temperature and other items but also can run a comprehensive preinspection readiness key. 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.
The AL539 found the fault I introduced into my 2014 Audi Allroad and was able to turn off the car's check engine light. With a one-year warranty, the AL539 is a dual-purpose scanner that can find more than OBD faults.
3. SeekOne SK860
Get a large color screen and a lifetime warranty
Display/size: Color/2.8 inches | Bluetooth/handheld: No/yes | I/M Readiness test: Yes | Displays live data: Yes | Number of keys: 8 | Warranty: Lifetime | Size: 7.8 x 3.8 x 1.2 inches | Weight: 11.2 ounces
Its large color screen, range of tasks, lifetime warranty and ease of use make the SeekOne SK860 a winner and one of the best OBD2 scanners around.
The price for this is a handheld scanner that at 7.8 x 3.8 x 1.2 inches and 11.2 ounces 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 preinspection readiness key along with a green (no-fault codes), yellow (intermittent problems) and red (permanent-problem codes) LED scheme. It examined the battery and showed live data, like engine speed, oxygen sensor readings and coolant temperature, then found my introduced fault and turned off the check engine light.
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.
4. Autophix Code Reader OM126
Lifetime software updates at the right price
Display/size: Color/2.4 inches | Bluetooth/handheld: No/yes | I/M Readiness test: Yes | Displays live data: Yes | Number of keys: 4 | Warranty: 3 years | Size: 4.8 x 3.0 x 0.9 inches | Weight: 9.0 ounces
Despite being among the most affordable and best OBD2 scanners available, the Autophix Code Reader OM126 includes a three-year warranty and lifetime software updates, allowing it to keep up with technological and model changes.
At 9 ounces and 4.8 x 3 x 0.9 inches, the OM126 is tiny compared with the likes of Nexpeak's NX501. Its protective bumpers give the scanner a rugged look that feels good in the hand, and its bright-orange color scheme should make it easy to find in a crowded toolbox. The OM126's 2.4-inch color screen shows six icons, but its four-key interface lacks right- and left-arrow keys, making navigation hard to figure out at first.
While the scanner's I/M readiness test for checking the car's major components doesn't have dedicated colored LEDs, it does display the results in an easy-to-read format. In addition to displaying live engine parameters, like engine speed and coolant temperature, it can graph them for comparison. Able to report generic and manufacturer-specific codes, the scanner can display oxygen sensor and battery data and easily found the fault I introduced in my car and turned off the check engine light.
Best of all, the OM126 lifetime's worth of software means it can help you diagnose car problems for years to come.
5. Autel MaxiAP AP200
A compact OBD scanner designed to work with your phone
Display/size: Single LED | Bluetooth/handheld: Yes/no | I/M Readiness test: Yes | Displays live data: Yes | Number of keys: N/A | Warranty: 1 year | Size: 1.9 x 1.1 x 0.9 inches | Weight: 1.1 ounces
Autel's $70 MaxiAP AP200 works with phones and tablets, and its rubber grips make the 1.9 x 1.1 x 0.9-inch device a snap to insert and remove from the car's OBD port. Small and light, it weighs 1.1 ounces and has a single LED to show it's online.
The AP200 connected via Bluetooth to my tablet on the first try with no passcode needed; there are apps for iOS and Android systems. The apps can provide a valuable window on car performance, but they were clearly written for phones with a vertical orientation and half-screen resolution on tablets. They can export items as Acrobat PDF documents.
The screen shows fault codes, has an I/M readiness test and displays live data, like engine speed and coolant temperature, which can be viewed as numbers, line graphs or realistic-looking automotive gauges. It has a 30-foot Bluetooth range but can take a frustratingly long 30 seconds to compile its data and 10 seconds to change tasks. It (slowly) found my introduced fault and turned off the check engine light — eventually.
6. BlueDriver Bluetooth Professional OBDII Scan Tool
This OBD2 scanner warns of recalls and makes repair suggestions
Display/size: Single LED | Bluetooth/handheld: Yes/no | I/M Readiness test: Yes | Displays live data: Yes | Number of keys: N/A | Warranty: 1 year | Size: 2.2 x 1.9 x 1.0 inches | Weight: 1.1 ounces
The BlueDriver Bluetooth Professional OBDII Scan Tool is pricier than some other models but can pay for itself with helpful recall warnings and repair suggestions.
Once connected, the BlueDriver's LED lights up, showing it's ready to perform preinspection emissions checking and interpret both the generic and the specialty fault codes for many of the major auto manufacturers. It can even count engine misfires on many newer cars, and the device's reports can be saved as PDF documents.
It quickly connected to my tablet, detected my car's fault and turned off the check engine light. The BlueDriver had a 32-foot Bluetooth range; the app is available for Android and iOS; and it can display speed, engine RPMs and other operational data as numbers or auto-oriented graphic gauges. My favorite feature is its Freeze Frame, which delivers a slice of data for analysis.
I liked the website's helpful videos, but the computer-synthesized voice proved to be annoying. If you don't mind the premium price, the BlueDriver Bluetooth Professional OBDII Scan Tool is one of the best OBD2 scanners you can buy.
A small size makes it easy to connect this OBD2 scanner
Display/size: 2 LEDs | Bluetooth/handheld: Yes/no | I/M Readiness test: Yes | Displays live data: Yes | Number of keys: N/A | Warranty: Lifetime | Size: 2.4 x 1.9 x 0.8 inches | Weight: 1.1 ounces
Don't let the DodyMPS' diminutive size and small price tag fool you. It is a powerful and easy-to-connect car scanner that includes a lifetime warranty and software updates.
The black OBD2 scanner has a small cutout with two LEDs and QR codes printed on its side for getting the needed Android and iOS apps. After downloading, installing and firing up the app, the software looked for the scanner and connected on the first try. DodyMPS showed my car's fault codes, extinguished the check engine light and ran a preinspection I/M readiness test. It showed live data, like coolant temperature and engine and car speed.
An inexpensive device, the DodyMPS cuts a few corners; for instance, its phone-centric app runs vertically at half resolution. On the other hand, it goes the extra mile with a lifetime warranty and software updates for new models and technologies.
8. Nexpeak OBD2 NX501
Built tough with a bright color display
Display/size: Color/2.8 inches | Bluetooth/handheld: No/yes | I/M Readiness test: Yes | Displays live data: Yes | Number of keys: 8 | Warranty: 3 years | Size: 7.6 x 3.8 x 1.3 inches | Weight: 1.6 pounds
The Nexpeak NX501 may be big and heavy, but it goes beyond the expected car checks with a long 5-foot OBD cable and lifetime software updates.
With soft rubber bumpers, the NX501 is ruggedly built and comfortable to use. Its three LEDs for the I/M preinspection test show green for no faults, yellow for a temporary problem or red to show a permanent fault. In addition to examinations of the battery and oxygen sensor, the NX501 interprets generic and many manufacturer-specific fault codes. The device quickly noticed the introduced fault on my car and turned off the car's check engine light.
At 2.8 inches, the NX501's display is bright with colorful icons for different features, and it can show everything from engine speed to coolant temperature along with colorful fever graphs. The tool's eight-key navigation makes it easy to move between scanning tasks. With its padded case, lifetime software upgrades and one of the longest OBD cables, the NX501 is one of the best OBD2 scanners for the money.
9. Konnwei KW850
A feature-rich scanner that can be a handful
Display/size: Color/2.8 inches | Bluetooth/handheld: No/yes | I/M Readiness test: Yes | Displays live data: Yes | Number of keys: 8 | Warranty: 2 years | Size: 7.8 x 3.8 x 1.2 inches | Weight: 11.2 ounces
Bearing more than a glancing similarity to the SeekOne SK860, the Konnwei KW850 OBD2 scanner is a good choice for those who want professional results on a budget.
One of the most thorough and reliable scanners available, the KW850 has rugged rubber bumpers, but it is large and a bit on the heavy side. Its 2.8-inch icon-based color screen and eight-key interface are easy to figure out and get used to.
The KW850 has an I/M preinspection button that illuminates red for a permanent fault, yellow for a temporary fault and green for a clean test. It displays and graphs live engine data, like speed, timing and coolant temperature, as well as showing battery information. The scanner can interpret generic and most manufacturer codes and immediately found my introduced fault and turned off the check engine light. With a padded case and extra-long 58-inch cable, the KW850 is well worth a look.
10. Foseal F0-01
When price counts for everything, this is a good, cheap OBD scanner
Display/size: Color/2.8 inches | Bluetooth/handheld: No/yes | I/M Readiness test: Yes | Displays live data: Yes | Number of keys: 6 | Warranty: 2 years | Size: 6.4 x 3.4 x 1.0 inches | Weight: 7.4 ounces
With a color display and handheld design, Foseal's F0-01 is one of the best OBD2 scanners for the money, but its 30-inch cable is short and can get in the way when you want to use it.
The F0-01 has a squared-off look with an inset for your thumb and grippy edges along the bottom that feel good in the hand and can help keep it from being dropped. At 6.4 x 3.4 x 1.0 inches and 7.4 ounces, the Foseal scanner is small, light and capable of living in a car's glove box. Up front, the F0-01's six-button interface has only up, down, OK and go-back keys. Oddly, there are shortcut keys to the car's VIN number and fault codes, but no problem warning light.
It quickly found my introduced fault, turned off the check engine light and can show live data as numbers or as line graphs. If you don't mind the 30-inch cable, the F0-01 costs about a tank of gas and could be the best $30 you can spend on your car.
How to choose the best OBD 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 an OBD2 scanner 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?
The best OBD 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 gear not only tells 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 OBD2 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 OBD2 scanners
To test the best OBD2 scanners, I used my 2014 Audi 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 OBD2 port, I made sure they could report the car's VIN code. 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 in.
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, like 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 OBD2 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 available 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.