The best OBD-II scanners are essential tools for modern car owners, acting as a vital link to your vehicle’s onboard computer. These devices decode the wealth of information your car diligently records, helping you understand everything from a simple dashboard warning light to complex engine issues. Instead of relying solely on expensive professional diagnostics, an OBD-II scanner empowers you to take a proactive approach to car maintenance and repair.
However, navigating the world of OBD-II scanners can be overwhelming. The market is flooded with options, each promising to be the best. Having rigorously tested a wide array of OBD-II scanners over the years, we’ve pinpointed the models that truly deliver on their promises. Below, we present our top recommendations, along with insights into how OBD-II scanners function and deciphering those often-cryptic error codes.
Among our top selections, the Topdon TopScan stands out as a remarkably effective wireless option for in-depth diagnostics. For budget-conscious users, the Launch CR529, priced around $40, offers exceptional value. And for those seeking professional-grade capabilities, the Topdon Phoenix Lite 2 delivers a comprehensive diagnostic experience, albeit at a premium price of $799.
Here’s a quick rundown of the best rated OBD-II scanners available today.
Tom Pritchard
Tom is the UK Phones Editor at Tom’s Guide, bringing expertise on mobile technology and a passion for electric vehicles to his automotive tech reviews.
Quick Recommendations – Top Best Rated OBD II Scanners
Based on our hands-on evaluations, here are the best OBD-II scanners you can purchase right now. Continue scrolling for detailed reviews of each product and why they earned their spot as top performers.
Topdon TopScan – best mobile scanner
1. Topdon TopScan
In our tests, the Topdon TopScan proved to be the easiest Bluetooth scanner to set up, while packing a suite of professional-grade features into a compact design. Expect comprehensive diagnostics, repair guidance, parts lists, and even predictive analysis to foresee potential issues.
Dive Deeper into the Topdon TopScan Review
Launch CR529 – best cheap scanner
2. Launch CR529
The Launch CR529 is a small yet mighty OBD-II scanner that delivers everything you need, plus some advanced features typically found in higher-priced models. Coupled with lifetime support and updates, this scanner offers incredible value for its price.
Explore the Launch CR529 Review Further
Topdon Phoenix Lite 2 – best rugged scanner
3. Topdon Phoenix Lite 2
Encased in a robust, horizontal design reminiscent of a Nintendo Switch, the Topdon Phoenix Lite 2 is built for both professionals and serious DIYers. More than just durable, it’s a powerful scanner designed to withstand demanding use.
Read More on the Topdon Phoenix Lite 2 Review
Ancel BD310 – best dual-purpose scanner
4. Ancel BD310
The Ancel BD310 excels as an OBD-II scanner and doubles as an auxiliary display for your car’s vital engine stats. Its sleek design, smartphone compatibility, and affordable price enhance its appeal.
Learn More in the Ancel BD310 Review
Carly OBD-II Scanner – best scanner with companion app
5. Carly OBD-II Scanner
The value of the Carly OBD-II Scanner is significantly boosted by its exceptional companion app. Especially beneficial for owners of VW, BMW, and Ford vehicles, Carly provides extensive customization and professional-level diagnostic tests.
Explore the Carly OBD-II Scanner Review
What Makes These OBD-II Scanners the Best?
Why Trust Tom’s Guide? Our team of expert reviewers dedicates countless hours to testing and analyzing products to bring you unbiased and reliable recommendations. Learn more about our rigorous testing methodology.
Best Mobile OBD-II Scanner
(Image credit: Topdon)
1. Topdon TopScan
Perfect for Deep Car Diagnostics
Read our Expert Review
Specifications:
- Display/size: None
- Bluetooth/handheld: Yes/No
- I/M Readiness test: Yes
- Displays live data: Yes
- Number of keys: None
- Warranty: 2 year
- Size: 3.2 x 2.0 x 1.1 inches
- Weight: 2.6 ounces
Reasons to Buy:
- Excellent automotive diagnostic coverage
- Real-time live data display
- Unique performance indicators
- Comprehensive maintenance item coverage
Reasons to Avoid:
- Larger transmitter size and weight
- Subscription required for some features after one year
The Topdon TopScan might appear unassuming at first glance, but this compact scanner packs a powerful punch. More than just a standard Bluetooth OBD-II module that streams data to your smartphone app, the TopScan significantly surpasses the capabilities of its competitors in the same class.
Beyond basic fault detection and I/M Readiness tests, the TopScan excels in performance and efficiency analysis. It can even estimate your vehicle’s horsepower and torque – features rarely found in OBD-II scanners, even those costing ten times more. Whether you’re aiming to optimize your car’s performance or simply ensure its roadworthiness, the Topdon TopScan is an invaluable tool to have.
Read our comprehensive Topdon TopScan review
Best Cheap OBD-II Scanner
(Image credit: Future)
2. Launch CR529
Top OBD-II Scanner Under $50
Read our Expert Review
Specifications:
- Display/size: Color/ 2.8-inches
- Bluetooth/handheld: No/Yes
- I/M Readiness test: Yes
- Displays live data: Yes
- Number of keys: 8
- Warranty: 1 year
- Size: 6.5 x 3.8 x 1.2 inches
- Weight: 11 ounces
Reasons to Buy:
- Very affordable
- Lifetime free updates
- Easy pre-inspection reporting
Reasons to Avoid:
- Lacks manufacturer-specific codes
- Feels somewhat heavy
- Limited 1-year warranty
The Launch CR529 is arguably the best value OBD-II scanner on the market. Its affordable price tag of around $38 is just the beginning; the diagnostic capabilities it offers at this price point are truly remarkable. The level of features you get for such a minimal investment is genuinely surprising.
Of course, some compromises are expected with such an economical scanner. It doesn’t support manufacturer-specific codes, and its handheld build feels a bit weighty. However, it still provides crucial features like live data, instant vehicle inspection reports, and a surprisingly detailed view into your car’s internal systems. The inclusion of lifetime updates, without any subscription fees, ensures long-term usability.
While the CR529 may not satisfy users with professional automotive diagnostic needs, it’s an excellent choice for the average car owner looking for a reliable and budget-friendly OBD-II scanner for their toolbox.
Read our full Launch CR529 review
Best Pro-Level OBD-II Scanner
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(Image credit: Future)](https://target.georiot.com/Proxy.ashx?tsid=45724&GR_URL=https%3A%2F%2Famazon.com%2Fdp%2FB085TG89H4%3Ftag%3Dhawk-future-20%26ascsubtag%3Dtomsguide-us-6624740130487362149-20)
3. Topdon Phoenix Lite 2
Bridging the Gap Between Amateur and Professional Diagnostics
Read our Expert Review
Specifications:
- Display/size: Color/8-inch
- Bluetooth/handheld: Yes/Yes
- I/M Readiness test: Yes
- Displays live data: Yes
- Number of keys: Touchscreen
- Warranty: 2 years
- Size: 10.2 x 7.2 x 1.7 inches
- Weight: 2.6 pounds
Reasons to Buy:
- Professional-grade OBD scanner features
- Hybrid handheld with Wi-Fi and Bluetooth
- Large 8-inch touchscreen display
- Extensive range of diagnostic tests and live data
- Includes adapters and a protective hard case
Reasons to Avoid:
- Bulky, heavy, and can be cumbersome
- High price point
- Subscription required after two years for updates
The Topdon Phoenix Lite 2 comes with a significant price tag compared to other OBD-II scanners, but it justifies the investment with its extensive features. It’s designed to cater to both amateur car enthusiasts and professional mechanics seeking in-depth diagnostic capabilities.
A standout feature is its wireless operation. The control pad connects via Bluetooth to a receiver plugged into your car’s OBD port, offering exceptional freedom of movement around the vehicle. While the scanner itself is substantial in size and weight, it includes a kickstand and rugged construction to withstand workshop environments.
The Phoenix Lite 2 also boasts live data graphing, detailed fault information, and advanced functions rarely found in more affordable scanners. Keep in mind that firmware updates are included for two years, after which an annual subscription of $495 is necessary.
Read our detailed Topdon Phoenix 2 Lite review
Best Dual-Purpose OBD-II Scanner
Ancel BD310 (Image credit: Tom’s Guide)
4. Ancel BD310
A Versatile OBD-II Scanner with Added Functionality
Read our Expert Review
Specifications:
- 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
Reasons to Buy:
- Lightweight and compact design
- Functions as both a scanner and secondary car display
- Offers handheld and Bluetooth scanning options
Reasons to Avoid:
- Minimalist interface design
- Small screen size
The Ancel BD310 is a versatile dual-purpose scanner that operates as a standard handheld device and can connect to smartphones via Bluetooth. Impressively, it can also transform into a secondary display, showing critical engine data directly in your car’s cabin.
Its compact and lightweight design makes the BD310 incredibly portable and easy to store in your glovebox. The 2-inch screen is admittedly small, and the four-button interface is somewhat basic, but these factors don’t hinder its diagnostic capabilities.
The 56-inch cable offers ample reach while working under the hood, and the BD310 effectively performs essential functions like I/M inspection readiness tests and provides performance metrics including coolant temperature, engine timing, and speed.
Read our full Ancel BD310 review.
Best Scanner with Companion App
(Image credit: Carly)
5. Carly OBD-II Scanner
Car Compatibility is Key to This Scanner’s Value
Read our Expert Review
Specifications:
- Display/Size: No
- Bluetooth/Handheld: Yes/No
- I/M Readiness Test: No
- Displays live data: Yes
- Number of keys: None
- Warranty: Lifetime
- Size: 2.9 x 1.5 x 0.7 inches
- Weight: 0.7 ounces
Reasons to Buy:
- User-friendly interface
- Extensive customization options
- Live data display
- Maintenance and repair assistance
- Lifetime warranty and updates
Reasons to Avoid:
- Feature availability varies by car model
- App subscription can be expensive
The Carly OBD Scanner provides a wealth of features, enhanced significantly by its outstanding companion app. Unlike many Bluetooth scanners with rudimentary apps, Carly boasts one of the most sophisticated and user-friendly apps we’ve tested.
Beyond basic diagnostics and clearing fault codes, the app offers repair assistance, tools to assess used cars for potential issues, and a lifetime warranty—a rare and highly valuable feature.
The primary limitation is feature compatibility, which varies depending on your car’s make and model. It’s crucial to confirm compatibility before purchasing. Additionally, accessing advanced features beyond basic OBD functions requires an ongoing app subscription, which can add to the overall cost.
Read our complete Carly OBD scanner review
Other Highly Rated OBD-II Scanners We Tested
Innova CarScan Mobile 1000 review Innova CarScan Mobile 1000 (★★★★☆)
The Innova CarScan Mobile 1000 stands out as an innovative Bluetooth OBD-II scanner, delivering Innova’s renowned features, including predictive diagnostics, wirelessly via your smartphone. Its incredibly simple setup process makes it a compelling Bluetooth-only option.
Read the full Innova CarScan Mobile 1000 review
ThinkCar ThinkDiag TKD01 (★★★★☆)
Despite being larger than typical Bluetooth OBD-II scanners, the ThinkCar ThinkDiag TKD01’s robust build makes it exceptionally durable. It offers a wide range of manufacturer-specific error codes and advanced fault codes that can resolve minor issues without needing a mechanic. A subscription of $40 per year is required after the first year.
Read our full ThinkCar ThinkDiag TKD01 review.
Autel AutoLink AL539 (★★★☆☆)
The Autel AutoLink AL539 OBD-II scanner is specifically designed for diagnosing electrical problems, enhanced by an integrated multimeter. It can identify issues like damaged cables, short circuits, and blown fuses. It also provides extensive live data and pre-inspection readiness checks.
Read our full Autel AutoLink AL539 review
Frequently Asked Questions About OBD-II Scanners
What is an OBD-II Scanner?
OBD-II scanners are diagnostic tools that mechanics and car owners use to understand a vehicle’s health. Instead of manually disassembling parts, these scanners connect to your car’s OBD port, accessing data from the onboard computer.
At their core, OBD-II scanners read and interpret Diagnostic Trouble Codes (DTCs) flagged by your car when it detects a problem. More advanced scanners offer real-time system monitoring and can even predict potential future issues.
What is the OBD-II Port?
The On-Board Diagnostics Version Two (OBD-II) port is a standardized interface found in nearly all passenger vehicles sold in the U.S. since 1996, Canada since 1998, the EU since 2004, and Australia, Mexico, and New Zealand since 2006.
This port serves as the connection point to your car’s onboard computer. Besides OBD-II scanners, it’s used for various devices like insurance telematics and dash cams.
If you’re unsure of its location, here’s a guide to finding the OBD-II port in North American vehicles. For locations worldwide, consult this resource on finding your OBD-II/EOBD port globally.
What is a DTC?
DTC stands for Diagnostic Trouble Code. It’s an error code generated by your car’s OBD system when it identifies a malfunction. OBD-II scanners read these codes, enabling users to diagnose vehicle issues. Many DTCs are standardized across vehicle makes and models, but some manufacturers use proprietary DTCs specific to their vehicles.
What do DTCs Actually Mean?
DTCs might seem like random combinations of letters and numbers, but they follow a logical structure that can help you understand the nature of the problem.
The first character indicates the affected vehicle system: Powertrain (P), Body (B), Chassis (C), or Network (N). The second character is a number: (0) for generic codes and (1) for manufacturer-specific codes.
The third character specifies the subsystem involved:
- 1: Fuel and air metering
- 2: Injector circuit fuel and air metering
- 3: Ignition system or misfire
- 4: Auxiliary emissions
- 5: Vehicle speed controls and idle control systems
- 6: Computer auxiliary outputs
- 7, 8, 9: Transmission and gearbox faults
- A, B, C: Hybrid-specific propulsion faults
The fourth and fifth characters pinpoint the exact fault, ranging from 0 to 99.
OBD-II scanners translate these codes into understandable descriptions. Advanced models provide more detailed information. While scanners offer explanations, further research on Google may be needed, given the vast number of possible DTCs—over 5,000.
Not all DTCs signal critical problems. While they can indicate major malfunctions, some codes may simply warn of minor issues like a slightly elevated engine temperature.
How to Choose the Best Rated OBD-II Scanner for You
For insights into your car’s operation and potential problems, using one of the best rated OBD-II scanners is highly effective.
These are the same tools dealerships and repair shops use for diagnostics. Why not have the same capability? OBD-II scanners come in two primary types:
Handheld OBD-II scanners have an integrated screen and connect via cable to your car’s OBD port. Wireless OBD-II scanners plug into the port and use Bluetooth to connect to a smartphone or tablet for displaying data.
Regardless of the type, numerous high-performance OBD-II scanners are available under $200, with some costing less than $30. Key factors to consider when choosing the best rated OBD-II scanner include:
- Easy Setup: A scanner that’s quick to set up encourages frequent use for early problem detection.
- Faults and Explanations: Top scanners not only identify faults but also explain their meaning, aiding DIY repairs or informing mechanic consultations.
- I/M Readiness Check: A valuable feature for verifying emissions system readiness for state inspections.
- Accuracy: Reliable results are paramount; inaccurate data is worse than no data.
- Size and Weight: Portability ensures the scanner is readily available in your car for on-the-go diagnostics.
- Live Data: Essential for tracking intermittent issues by monitoring real-time engine parameters.
- Graphs: Visual data representation enhances understanding, especially for comparative analysis.
- Warranty: A good warranty reflects product quality and long-term reliability, ideally matching the lifespan of your vehicle.
Deciding between handheld and wireless scanners is the first step. Consider models with lifetime warranties or software updates for longevity and compatibility with evolving automotive technology.
For handheld scanners, prioritize screen size and clarity for easy readability. Rugged models with rubber bumpers offer added durability.
Explore additional features like electrical multimeters, manufacturer-specific code reading, and PDF report export capabilities.
The affordability of these sophisticated devices, often under $100, makes them a cost-effective alternative to professional mechanic diagnostic fees.
How We Test OBD-II Scanners
To rigorously evaluate OBD-II scanners, we conducted tests using a 2014 Audi A4 Allroad over several weeks in various driving conditions. Each scanner was connected to the car’s OBD-II port, verifying its ability to read the Vehicle Identification Number (VIN).
Wireless scanners were paired with an Apple iPad Pro, Microsoft Surface, or Samsung Galaxy S9+ via Bluetooth or Wi-Fi. Handheld scanners were simply plugged into the OBD-II port, drawing power directly.
We measured cable lengths for handheld models and wireless range for Bluetooth scanners. With the engine running, we monitored engine performance and vital systems before intentionally disconnecting the engine oil temperature sensor to trigger a fault code.
We then assessed the scanner’s ability to identify and explain the fault, cleared the error code after reconnecting the sensor, and observed real-time operating data like engine speed, timing, and coolant temperature in both numerical and graphical formats during road tests.
Understanding fault codes is crucial. All codes consist of five characters: a letter prefix and four numbers.
- P (Powertrain)
- B (Body)
- C (Chassis)
- U (Undefined)
Of the approximately 5,000 possible diagnostic fault codes, some are generic (starting with ‘0’) and apply across all vehicles, like air temperature sensor issues. Others are manufacturer-specific (starting with ‘1’) for specialized components or in-depth problem analysis.
For example, a P0098 code typically indicates an issue with the intake air temperature sensor. In contrast, a Ford-specific P1112 code points to intermittent readings from the intake air temperature sensor, suggesting replacement.
