The best OBD-II scanners are essential tools for modern car owners, offering a direct line to your vehicle’s onboard computer. These devices decode the data, revealing insights into your car’s health, from simple dashboard warnings to complex mechanical issues. Instead of relying solely on expensive professional diagnostics, a top-rated OBD II scanner empowers you to understand and address car problems yourself.
Navigating the world of OBD-II scanners can be daunting, especially for beginners. The market is flooded with options, each promising to be the best. Fortunately, we’ve rigorously tested a wide array of OBD-II scanners over the years. Our hands-on experience allows us to confidently guide you towards the top-rated OBD II scanners that are truly worth your investment. Keep reading to discover our top picks, understand how these scanners work, and decipher those mysterious error codes.
Among our top selections, the Topdon TopScan stands out as a wireless marvel, offering impressive diagnostic capabilities in a user-friendly package. For budget-conscious users, the Launch CR529, priced around $40, delivers exceptional value and features. If you’re seeking a professional-grade experience, the Topdon Phoenix Lite 2 provides advanced diagnostics comparable to professional tools, albeit at a premium price of $799.
Below, we present our curated list of the Top Rated Obd Ii Scanners currently available.
Tom Pritchard
Tom is the UK Phones Editor for Tom’s Guide, with expertise spanning from the latest gadgets to essential mobile apps. A passionate advocate for electric vehicles, he brings extensive knowledge of automotive technology to his reviews.
Top Rated OBD II Scanners: Quick Picks
Based on extensive hands-on testing, here are our top recommendations for the best OBD-II scanners you can purchase today. Continue scrolling for detailed reviews of each scanner and insights into their standout features.
Topdon TopScan: Best Mobile OBD II Scanner1. Topdon TopScan
Effortless Bluetooth connectivity and a suite of professional-grade features are packed into the Topdon TopScan’s compact design. Enjoy comprehensive diagnostics, repair guidance, parts information, and even predictive analysis to anticipate potential issues before they escalate.
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Launch CR529: Best Budget OBD II Scanner2. Launch CR529
The Launch CR529 is a small yet mighty OBD-II scanner that delivers essential functionalities and unexpected high-end features for its price range. Benefit from lifetime support and updates, making this scanner an exceptional value proposition.
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Topdon Phoenix Lite 2: Best Professional-Grade OBD II Scanner3. Topdon Phoenix Lite 2
Resembling a rugged tablet, the Topdon Phoenix Lite 2 is designed for both professionals and serious DIYers. This robust device offers powerful scanning capabilities and withstands demanding workshop environments.
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Ancel BD310: Best Dual-Purpose OBD II Scanner4. Ancel BD310
The Ancel BD310 serves as both a reliable OBD-II scanner and an auxiliary dashboard display. Enjoy its sleek design, smartphone compatibility, and affordable price point for versatile car diagnostics.
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Carly OBD-II Scanner: Best OBD II Scanner with Companion App5. Carly OBD-II Scanner
The Carly OBD-II Scanner’s utility is maximized with specific car brands like VW, BMW, and Ford, offering extensive features. Its standout companion app provides exceptional customization and professional-level diagnostic tests.
Deep Dive into the Top Rated OBD II Scanners
Why Trust Tom’s Guide Reviews? Our dedicated team of writers and editors invests significant time in evaluating products, services, and apps to deliver trustworthy recommendations. Learn more about our rigorous testing and rating methodologies.
1. Topdon TopScan: Best Mobile OBD-II Scanner
(Image credit: Topdon)
Key Features:
- Display/Size: None (App-based)
- Bluetooth/Handheld: Yes/No
- I/M Readiness Test: Yes
- Live Data Display: Yes
- Number of Keys: None (App-based)
- Warranty: 2 years
- Size: 3.2 x 2.0 x 1.1 inches
- Weight: 2.6 ounces
Pros:
- Excellent vehicle diagnostic coverage
- Displays live data streams
- Unique performance indicators
- Comprehensive maintenance item coverage
Cons:
- Larger transmitter size
- Some advanced features require subscription after the first year
The Topdon TopScan may appear unassuming at first glance, but this compact scanner is packed with features that go far beyond basic OBD-II functionality. This isn’t just a standard Bluetooth OBD-II adapter; it’s a sophisticated tool that rivals scanners in higher price brackets.
Beyond reading fault codes and performing 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 at this price point.
Whether you’re focused on optimizing your car’s performance or ensuring its roadworthiness, the Topdon TopScan is a valuable addition to any car owner’s toolkit.
Read our in-depth Topdon TopScan review
2. Launch CR529: Best Cheap OBD-II Scanner
(Image credit: Future)
Key Features:
- Display/Size: Color/ 2.8-inches
- Bluetooth/Handheld: No/Yes
- I/M Readiness Test: Yes
- Live Data Display: Yes
- Number of Keys: 8
- Warranty: 1 year
- Size: 6.5 x 3.8 x 1.2 inches
- Weight: 11 ounces
Pros:
- Very affordable
- Lifetime free updates
- Easy pre-inspection report generation
Cons:
- Lacks manufacturer-specific codes
- Feels somewhat heavy
- Limited 1-year warranty
The Launch CR529 redefines value in OBD-II scanners. Priced under $50, it offers a surprising array of diagnostic features that belie its affordability. The level of functionality packed into this budget-friendly scanner is truly impressive.
While compromises are expected at this price point, such as the absence of manufacturer-specific codes and a slightly heavier feel, the CR529 still delivers essential features. It provides live data streaming, an instant inspection function, and surprisingly detailed insights into your vehicle’s systems. Furthermore, lifetime updates ensure long-term usability without subscription fees.
Although the CR529 might not cater to professional mechanics seeking advanced features, it’s an excellent choice for everyday car owners seeking a reliable and affordable diagnostic tool.
Read our comprehensive Launch CR529 review
3. Topdon Phoenix Lite 2: Best Professional-Grade OBD-II Scanner
Topdon Phoenix Lite 2 Scanner in Action
(Image credit: Future)
Key Features:
- Display/Size: Color/8-inch Touchscreen
- Bluetooth/Handheld: Yes/Yes (Wireless Connectivity)
- I/M Readiness Test: Yes
- Live Data Display: Yes
- Number of Keys: Touchscreen Interface
- Warranty: 2 years
- Size: 10.2 x 7.2 x 1.7 inches
- Weight: 2.6 pounds
Pros:
- Professional-grade OBD scanner capabilities
- Hybrid handheld with Wi-Fi and Bluetooth
- Large 8-inch touchscreen display
- Extensive range of diagnostic tests and live data parameters
- Includes adapters and a hard protective case
Cons:
- Bulky and heavy design, can be cumbersome
- Higher price point
- Subscription required for updates after two years
The Topdon Phoenix Lite 2 commands a higher price than many OBD-II scanners, but it justifies the investment with a wealth of advanced features. This scanner bridges the gap between amateur and professional diagnostics, making it suitable for both experienced mechanics and serious car enthusiasts.
A standout feature is its wireless operation; the control pad communicates via Bluetooth with a receiver plugged into the OBD port, providing exceptional freedom of movement around the vehicle. While the scanner itself is substantial in size and weight, it incorporates a kickstand and rugged construction to withstand demanding workshop conditions.
The Phoenix Lite 2 offers advanced functionalities like live data graphing, detailed fault code information, and capabilities typically reserved for high-end scanners. However, note that firmware updates are included for two years, after which an annual subscription of $495 is required.
Explore our detailed Topdon Phoenix 2 Lite review
4. Ancel BD310: Best Dual-Purpose OBD-II Scanner
Ancel BD310 (Image credit: Tom’s Guide)
Key Features:
- Display/Size: Color/2 inches
- Bluetooth/Handheld: Yes/Yes
- I/M Readiness Test: Yes
- Live Data Display: Yes
- Number of Keys: 4
- Warranty: 3 years
- Size: 5.1 x 2.4 x 0.6 inches
- Weight: 5.4 ounces
Pros:
- Lightweight and compact for portability
- Functions as both a scanner and a secondary car display
- Offers handheld and Bluetooth scanning options
Cons:
- Minimalist interface design
- Small screen size
The Ancel BD310 distinguishes itself with its dual functionality, operating as a standard handheld OBD-II scanner and also connecting to smartphones via Bluetooth. Furthermore, it can transform into a supplementary display within your car, showing essential engine parameters in real-time.
Its compact and lightweight design makes the BD310 exceptionally portable; it easily fits in a glovebox. While the 2-inch screen is small and the four-button interface is somewhat basic, these factors don’t hinder its diagnostic capabilities.
The 56-inch cable provides ample reach for working around the engine bay. The BD310 effectively performs essential diagnostic tasks, including I/M readiness checks and displaying performance data like coolant temperature, engine timing, and RPM.
Explore our full Ancel BD310 review.
5. Carly OBD-II Scanner: Best OBD II Scanner with Companion App
(Image credit: Carly)
Key Features:
- Display/Size: None (App-based)
- Bluetooth/Handheld: Yes/No
- I/M Readiness Test: No
- Live Data Display: Yes
- Number of Keys: None (App-based)
- Warranty: Lifetime
- Size: 2.9 x 1.5 x 0.7 inches
- Weight: 0.7 ounces
Pros:
- User-friendly interface
- Extensive customization options within the app
- Live data visualization
- Covers maintenance and repair procedures
- Lifetime warranty and software updates
Cons:
- Feature availability varies by car model
- App subscription can be costly for full functionality
The Carly OBD Scanner excels with its exceptional companion app, setting it apart from many Bluetooth OBD-II scanners with basic app interfaces. Carly provides one of the most feature-rich and user-friendly apps we’ve tested.
Beyond basic fault code reading and clearing, the Carly app offers repair guidance, used car check features to identify potential problems, and a lifetime warranty, a rare and valuable offering.
However, the range of features supported depends on your car’s make and model. Compatibility is most extensive with brands like VW, BMW, and Ford. While the app is outstanding, accessing advanced features beyond basic OBD functions requires an ongoing subscription, which can add to the overall cost.
Read our complete Carly OBD scanner review
Other OBD-II Scanners We’ve Tested
- Innova CarScan Mobile 1000 (★★★★☆): A highly innovative Bluetooth OBD-II scanner from Innova, offering predictive diagnostics wirelessly through your smartphone. Easy setup and impressive features make it a compelling Bluetooth option. Read the full Innova CarScan Mobile 1000 review.
- ThinkCar ThinkDiag TKD01 (★★★★☆): While larger than typical Bluetooth OBD-II adapters, the TKD01 is built to be durable. It offers extensive manufacturer-specific error codes and advanced fault code analysis, potentially resolving minor issues without mechanic intervention. A $40 subscription is required after the first year. Read our full ThinkCar ThinkDiag TKD01 review.*
- Autel AutoLink AL539 (★★★☆☆): Specifically designed for electrical diagnostics, this OBD-II scanner includes a built-in multimeter for identifying electrical issues like shorts, blown fuses, and damaged wiring. It also provides comprehensive 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?
Mechanics use diagnostic scanners plugged into your car’s OBD port to understand car problems, rather than manually disassembling the engine. These scanners access your car’s onboard computer to retrieve diagnostic information.
Basic OBD-II scanners read and interpret error codes generated by your car when it detects an issue. Advanced scanners offer real-time system monitoring and can even predict potential future problems.
What is the OBD-II Port?
The On-Board Diagnostics Version Two (OBD-II) port is a standardized port found in most passenger vehicles sold in the US since 1996, Canada since 1998, EU since 2004, and Australia, Mexico, and New Zealand since 2006.
This port serves as the interface to your car’s onboard computer. It accommodates various devices, including OBD-II scanners, insurance telematics devices, and modern dash cams.
If you’re unsure of your OBD-II port’s location, find a guide on locating your car’s OBD-II port for North American vehicles, or worldwide OBD-II/EOBD port locations.
What is a DTC?
DTC stands for Diagnostic Trouble Code. These error codes are generated by a car’s OBD system when it detects a malfunction. OBD-II scanners read these codes to help users diagnose car issues. While many DTCs are standardized across vehicle makes and models, some manufacturers use proprietary DTCs specific to their vehicles.
Understanding DTC Meanings
DTCs may seem like random combinations of letters and numbers, but they follow a logical structure to indicate the nature of the problem.
The first letter designates the affected vehicle system: Powertrain (P), Body (B), Chassis (C), or Network (N). The second character, a number, indicates whether the code is generic (0) or manufacturer-specific (1).
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
- 6: Computer auxiliary outputs
- 7, 8, 9: Transmission and gearbox
- A, B, C: Hybrid propulsion systems
The fourth and fifth characters pinpoint the exact fault with a numerical code from 0 to 99.
OBD-II scanners translate these codes into understandable descriptions. Advanced scanners provide more detailed information. Online resources like Google can also help decipher DTCs. There are over 5,000 possible DTCs, covering a wide range of potential car problems.
Not all DTCs indicate critical issues. While some signal major malfunctions, others might simply warn of minor anomalies like slightly elevated engine temperature.
Choosing the Right Top Rated OBD II Scanner
For insights into your vehicle’s operation and potential problems, using a top rated OBD II scanner is an effective approach.
This is the same method dealerships and repair shops use to diagnose car issues. Having this capability yourself can be highly beneficial. OBD-II scanners come in two main types:
Handheld OBD-II scanners feature an integrated screen and a cable for connecting to the OBD port. Wireless OBD-II scanners plug into the OBD port and use Bluetooth to transmit data to a smartphone or tablet for display.
Regardless of the type, numerous high-quality OBD-II scanners are available for under $200, and some even for under $30. Key factors to consider when selecting a top rated OBD II scanner include:
- Easy Setup: A scanner should be quick and easy to set up for prompt diagnostics.
- Fault Code Explanation: Top rated scanners not only identify fault codes but also provide explanations to help you understand the issue and guide repair decisions.
- I/M Readiness Check: A valuable feature for pre-inspection testing to ensure your vehicle will pass emissions and safety checks.
- Accuracy: Reliable and accurate readings are crucial for effective diagnostics.
- Size and Weight: A compact and lightweight scanner is more convenient for in-car use and storage.
- Live Data: The ability to monitor real-time engine data streams helps in diagnosing intermittent problems.
- Graphs: Visual data representations, like graphs, can enhance data analysis and comparison.
- Warranty: Look for scanners with a solid warranty, ideally lifetime or extended coverage, to ensure long-term reliability.
Choosing between handheld and wireless scanners depends on personal preference. Consider factors like screen size (for handhelds), ease of use, and desired features.
Prioritize scanners with lifetime updates to stay current with evolving automotive technology. For handheld scanners, opt for a large, clear, and user-friendly display. Ruggedness and durability are also important, especially for frequent use.
Consider extra features like built-in multimeters, manufacturer-specific code reading, and PDF report generation. The price range for top rated OBD II scanners is surprisingly affordable, often under $100, making them a cost-effective tool compared to professional diagnostic services.
Our OBD-II Scanner Testing Methodology
To evaluate OBD-II scanners, we used a 2014 Audi A4 Allroad over several weeks in various driving conditions. Each scanner was connected to the car’s OBD-II port to verify VIN reporting.
Wireless scanners were paired with an Apple iPad Pro, Microsoft Surface, or Samsung Galaxy S9+ via Bluetooth or Wi-Fi. Handheld scanners were tested by direct OBD-II port connection, drawing power from the port itself.
Cord lengths of handheld scanners and wireless ranges of Bluetooth models were measured. With the engine running, engine parameters and vital systems were monitored. The engine oil temperature sensor was intentionally disconnected to trigger a fault code.
The scanners’ ability to accurately report and explain the fault code was assessed. After troubleshooting, the check engine light was cleared and the error code erased using the scanner.
Finally, on-road testing evaluated live data display, including engine speed, timing, and coolant temperature, noting data presentation formats (numerical, graphs, gauges).
Understanding OBD-II Fault Codes
All fault codes consist of a letter prefix and four numbers:
- Powertrain (P)
- Body (B)
- Chassis (C)
- Undefined (U)
Of the approximately 5,000 possible diagnostic fault codes, generic codes (starting with ‘0’) are common across all vehicles, such as those for air temperature or throttle position sensors. Manufacturer-specific codes (starting with ‘1’) are unique to specific carmakers and often indicate more detailed or manufacturer-specific issues.
For example, a P0098 code typically points to an issue with the intake air temperature sensor. Conversely, a Ford-specific P1112 code indicates an intermittent intake air temperature sensor reading, suggesting sensor replacement.
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