The best OBD-II scanners are essential tools for any car owner wanting to understand their vehicle’s health. Modern cars are complex computers on wheels, and when something goes wrong, your car’s onboard diagnostic system is usually the first to know. An OBD-II scanner acts as a bridge, connecting you to this hidden information, allowing you to diagnose problems and potentially save money on repair costs. Whether you’re seeing a mysterious dashboard light or experiencing performance issues, an OBD-II scanner can give you the insights you need.
Navigating the world of OBD-II scanners can be overwhelming, especially for beginners. With countless options available, it’s hard to know which scanner is right for you. We’ve spent years testing a wide variety of OBD-II scanners, from basic code readers to professional-grade tools. Our hands-on experience allows us to confidently recommend the best OBD-II scanners available today.
Our top recommendations include the Topdon TopScan, a wireless marvel that’s incredibly user-friendly and packed with diagnostic power. If budget is a concern, the Launch CR529 offers exceptional value without sacrificing essential features. For those seeking professional-level diagnostics, the Topdon Phoenix Lite 2 delivers a comprehensive experience, albeit at a higher price point.
Below are our curated selections for the best OBD-II scanners currently on the market. Keep scrolling to discover detailed reviews of each pick and a comprehensive guide to understanding how OBD-II scanners work and deciphering those cryptic error codes.
Tom Pritchard
Tom is the UK Phones Editor for Tom’s Guide, covering mobile technology and apps. He’s also a passionate advocate for electric vehicles and deeply involved in automotive tech.
Quick Recommendations: The Best OBD-II Scanners at a Glance
Here’s a quick rundown of the best OBD-II scanners you can buy now, based on our rigorous testing. For detailed reviews and deeper insights, simply scroll down.
topdon topscan mobile OBS2 scannerTopdon TopScan: Best Mobile OBD-II Scanner 1. Topdon TopScan: Best Mobile OBD-II Scanner
The Topdon TopScan stands out as the easiest Bluetooth OBD-II scanner to set up and use. Despite its compact size, it boasts a range of professional-grade features, including comprehensive diagnostics, repair guidance, parts lists, and even predictive analysis to anticipate potential issues.
Dive Deeper into the Topdon TopScan Review
Launchcr529 obd-ii scanner on white backgroundLaunch CR529: Best Cheap OBD-II Scanner 2. Launch CR529: Best Cheap OBD-II Scanner
The Launch CR529 is a small yet powerful OBD-II scanner that delivers all the essential functionalities you expect, along with some advanced features typically found in more expensive models. Its lifetime support and updates make it an exceptionally valuable choice for budget-conscious users.
Explore the Launch CR529 Review
topdon phoenix lite 2 obd-ii scanner and tablet on a white backgroundTopdon Phoenix Lite 2: Best Pro-Level OBD-II Scanner 3. Topdon Phoenix Lite 2: Best Pro-Level OBD-II Scanner
The Topdon Phoenix Lite 2, with its robust design and horizontal tablet-like form factor, feels like a dedicated gaming device for your car’s computer. However, it’s more than just durable; it’s engineered for both professional mechanics and serious car enthusiasts seeking advanced diagnostic capabilities.
Read More About the Topdon Phoenix Lite 2
best obd2 scannersAncel BD310: Best Dual-Purpose OBD-II Scanner 4. Ancel BD310: Best Dual-Purpose OBD-II Scanner
The Ancel BD310 is a versatile tool that functions not only as an effective OBD-II scanner but also as a supplementary dashboard display, providing real-time engine specifications. Its sleek design, smartphone compatibility, and affordable price further enhance its appeal.
Discover the Ancel BD310 Features
carly obd scanner grid imageCarly OBD-II Scanner: Best OBD-II Scanner with Companion App 5. Carly OBD-II Scanner: Best OBD-II Scanner with Companion App
The Carly OBD-II Scanner’s utility is highly dependent on your car’s make, with Volkswagen, BMW, and Ford vehicles benefiting the most from its extensive features. Its standout feature is its exceptional companion app, offering a wide array of customization options and professional-grade diagnostic tests.
Learn More About the Carly OBD-II Scanner and App
Deep Dive: Exploring the Best OBD-II Scanners in Detail
Why Trust Tom’s Guide? Our team of expert reviewers dedicates countless hours to hands-on testing and in-depth analysis of products, services, and apps. Our goal is to provide you with reliable, unbiased information to help you make the best choices. Learn more about our rigorous testing methodology.
1. Best Mobile OBD-II Scanner: Topdon TopScan
topdon topscan obd scanner with bluetooth
(Image credit: Topdon)
Topdon TopScan: Unleash Your Car’s Hidden Potential
Expert Review:
Key Specifications:
- Display: None (relies on smartphone app)
- Connectivity: Bluetooth
- Handheld: No
- I/M Readiness Test: Yes
- Live Data Display: Yes
- Keys: None (app-controlled)
- Warranty: 2 years
- Dimensions: 3.2 x 2.0 x 1.1 inches
- Weight: 2.6 ounces
Reasons to Buy:
- Exceptional automotive diagnostic coverage
- Comprehensive live data monitoring
- Unique performance indicators and tests
- Maintenance item coverage and reminders
Reasons to Consider Other Options:
- The Bluetooth transmitter module is relatively large
- Advanced features may require a subscription after the first year
The Topdon TopScan might appear unassuming at first glance, but this compact scanner packs a surprising punch. It’s far more than a basic Bluetooth OBD-II adapter; it’s a sophisticated diagnostic tool that rivals scanners many times its price. We were particularly impressed by its ability to go beyond simple fault code reading, offering performance and efficiency checks, and even estimating horsepower and torque – features rarely seen in scanners in this price range.
Whether you’re a performance enthusiast looking to fine-tune your car or simply want to ensure your vehicle is in top condition, the Topdon TopScan is an invaluable tool to have in your garage.
Read our full Topdon TopScan review for a complete analysis.
2. Best Cheap OBD-II Scanner: Launch CR529
Launch cr259 obd–ii scanner
(Image credit: Future)
Launch CR529: Unbeatable Value Under $50
Expert Review:
Key Specifications:
- Display: 2.8-inch Color Screen
- Connectivity: None (Handheld)
- Handheld: Yes
- I/M Readiness Test: Yes
- Live Data Display: Yes
- Keys: 8 Physical Buttons
- Warranty: 1 year
- Dimensions: 6.5 x 3.8 x 1.2 inches
- Weight: 11 ounces
Reasons to Buy:
- Extremely affordable price point
- Lifetime free software updates
- Easy pre-inspection report generation
Reasons to Consider Other Options:
- Lacks manufacturer-specific diagnostic codes
- Feels somewhat heavy for its size
- Shorter 1-year warranty
The Launch CR529 redefines value in the OBD-II scanner market. For an incredibly low price, you get a surprising level of diagnostic capability. We were genuinely impressed by the features packed into this budget-friendly device. While compromises are expected at this price, the CR529 still delivers essential functionalities like live data, instant vehicle inspections, and a detailed look at your car’s internal systems. The inclusion of lifetime updates is a significant bonus, ensuring long-term usability without subscription fees.
While the CR529 might not satisfy professional mechanics seeking advanced manufacturer-specific codes, it’s an excellent choice for the average car owner looking for a reliable and affordable OBD-II scanner for home use.
Read our comprehensive Launch CR529 review to see why it’s our top budget pick.
3. Best Pro-Level OBD-II Scanner: Topdon Phoenix Lite 2
topdon phoenix lite 2 obd2 scanner over car engineTopdon Phoenix Lite 2 over car engine
(Image credit: Future)
Topdon Phoenix Lite 2: Bridging the Gap Between Amateur and Professional Diagnostics
Expert Review:
Key Specifications:
- Display: 8-inch Color Touchscreen
- Connectivity: Bluetooth, Wi-Fi
- Handheld: Yes
- I/M Readiness Test: Yes
- Live Data Display: Yes
- Keys: Touchscreen Interface
- Warranty: 2 years
- Dimensions: 10.2 x 7.2 x 1.7 inches
- Weight: 2.6 pounds
Reasons to Buy:
- Professional-grade OBD scanner features
- Versatile handheld design with Wi-Fi and Bluetooth
- Large 8-inch intuitive touchscreen
- Extensive suite of diagnostic tests and live data options
- Includes adapters and a protective hard case
Reasons to Consider Other Options:
- Bulky and heavy, potentially cumbersome for some users
- Higher price point compared to other scanners
- Subscription required for updates after two years
The Topdon Phoenix Lite 2 represents a significant step up in diagnostic capability. While it comes with a higher price tag, it delivers a near-professional diagnostic experience, making it suitable for both experienced mechanics and serious DIY enthusiasts. Its wireless operation is a standout feature, with a Bluetooth-connected control pad that allows for freedom of movement around the vehicle. The robust, workshop-ready design includes a kickstand for hands-free operation.
Beyond basic code reading, the Phoenix Lite 2 offers advanced features like live data graphing and in-depth fault analysis, typically found in professional-grade scanners. However, be mindful of the subscription requirement for firmware updates after the initial two years.
Explore our in-depth Topdon Phoenix 2 Lite review for a complete breakdown of its professional features.
4. Best Dual-Purpose OBD-II Scanner: Ancel BD310
Best OBD-II scanners: Ancel BD310
Ancel BD310 (Image credit: Tom’s Guide)
Ancel BD310: OBD-II Scanning and Secondary Display in One
Expert Review:
Key Specifications:
- Display: 2-inch Color Screen
- Connectivity: Bluetooth
- Handheld: Yes
- I/M Readiness Test: Yes
- Live Data Display: Yes
- Keys: 4 Physical Buttons
- Warranty: 3 years
- Dimensions: 5.1 x 2.4 x 0.6 inches
- Weight: 5.4 ounces
Reasons to Buy:
- Lightweight and highly compact design
- Functions as both a scanner and a secondary car display
- Offers both handheld and Bluetooth scanning modes
Reasons to Consider Other Options:
- Minimalist interface may lack visual appeal for some
- Small 2-inch screen can feel cramped
The Ancel BD310 offers a unique dual functionality, serving as both a standard handheld OBD-II scanner and a Bluetooth-connected secondary display for your car’s data. Its compact and lightweight design makes it incredibly convenient to store in your glovebox. While the 2-inch screen is small, it’s sufficient for displaying key diagnostic information. The BD310 is capable of performing essential functions like I/M readiness tests and displaying performance data, including coolant temperature, engine timing, and RPM.
Despite its minimalist interface and small screen, the Ancel BD310 is a practical and versatile OBD-II scanner, particularly appealing to users who appreciate its dual-purpose functionality and portability.
Read our full Ancel BD310 review to learn more about its unique features.
5. Best OBD-II Scanner with Companion App: Carly OBD-II Scanner
carly obd 2 scanner design
(Image credit: Carly)
Carly OBD-II Scanner: Unlock Advanced Features with a Powerful App
Expert Review:
Key Specifications:
- Display: None (relies on smartphone app)
- Connectivity: Bluetooth
- Handheld: No
- I/M Readiness Test: No (feature depends on car model)
- Live Data Display: Yes
- Keys: None (app-controlled)
- Warranty: Lifetime
- Dimensions: 2.9 x 1.5 x 0.7 inches
- Weight: 0.7 ounces
Reasons to Buy:
- User-friendly and intuitive app interface
- Extensive customization options within the app
- Real-time live data display
- Covers maintenance and repair procedures
- Lifetime warranty and software updates
Reasons to Consider Other Options:
- Feature availability varies significantly depending on car make and model
- App subscription can become expensive for full functionality
The Carly OBD Scanner distinguishes itself with its exceptional companion app. While many Bluetooth scanners offer basic apps, Carly provides one of the most feature-rich and user-friendly app experiences we’ve encountered. Beyond standard diagnostics, the app offers repair assistance, used car checks, and extensive customization. The lifetime warranty is a rare and valuable benefit.
However, the Carly’s functionality is heavily dependent on your car’s make and model, with certain brands like VW, BMW, and Ford enjoying the most comprehensive support. Unlocking the full potential of the Carly app requires a subscription, which can add to the overall cost.
Read our detailed Carly OBD scanner review to determine if it’s the right choice for your vehicle.
Other OBD-II Scanners We’ve Tested: Honorable Mentions
Innova CarScan Mobile 1000 (★★★★☆)
The Innova CarScan Mobile 1000 is a highly innovative Bluetooth OBD-II scanner, inheriting Innova’s renowned features, including predictive diagnostics. Its wireless design and incredibly simple setup make it a compelling Bluetooth-only option.
Read the full Innova CarScan Mobile 1000 review.
ThinkCar ThinkDiag TKD01 (★★★★☆)
ThinkCar ThinkDiag TKD01 (★★★★☆)
Despite its larger size for a Bluetooth OBD-II scanner, the ThinkCar ThinkDiag TKD01 is built to be exceptionally durable. It offers a wide range of manufacturer-specific error codes and advanced fault-code analysis that can even resolve minor issues automatically. A subscription is required after the first year.
Read our full ThinkCar ThinkDiag TKD01 review.
Autel AutoLink AL539 (★★★☆☆)
The Autel AutoLink AL539 is specifically designed for diagnosing electrical problems, thanks to its integrated multimeter. It excels at identifying issues like burnt cables, electrical shorts, 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 exactly is an OBD-II Scanner?
Mechanics rely on OBD-II scanners to diagnose car problems efficiently. Instead of manually inspecting every component, they connect a diagnostic scanner to your car’s OBD port to access data from the onboard computer.
Basic OBD-II scanners read and interpret error codes triggered by your car’s system when it detects a problem. More advanced scanners offer real-time system monitoring and even predict potential future issues. These tools empower car owners to understand their vehicle’s health and make informed repair decisions.
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 US since 1996, Canada since 1998, the EU since 2004, and Australia, Mexico, and New Zealand since 2006.
This port serves as the connection point for communicating with your car’s computer. OBD-II scanners, insurance telematics devices, and even some dash cams utilize this port.
If you’re unsure of its location, you can easily find your car’s OBD-II port location for North American vehicles. For other regions, consult resources on how to find your OBD-II/EOBD port worldwide.
Understanding DTCs: Diagnostic Trouble Codes
DTC stands for Diagnostic Trouble Code. These are error codes generated by your car’s OBD system when it detects a malfunction. OBD-II scanners read these codes, enabling users to pinpoint the source of the problem. While many DTCs are standardized across vehicle makes and models, some manufacturers use proprietary DTCs specific to their vehicles.
Deciphering DTC Meanings
DTCs may seem like random alphanumeric strings, but they follow a logical structure that reveals information about the detected error.
The first letter indicates the affected vehicle system:
- P: Powertrain (engine and transmission)
- B: Body (interior and exterior components)
- C: Chassis (brakes, suspension, steering)
- N: Network (communication systems)
The second character is a number: 0 for generic codes (standardized across manufacturers) and 1 for manufacturer-specific codes.
The third character specifies the subsystem:
- 1: Fuel and air metering
- 2: Injector circuit (fuel and air metering)
- 3: Ignition system or misfire
- 4: Auxiliary emissions control
- 5: Vehicle speed control and idle control systems
- 6: Computer auxiliary outputs
- 7, 8, 9: Transmission and gearbox faults
- A, B, C: Hybrid propulsion system faults
The fourth and fifth characters pinpoint the exact fault within the subsystem, ranging from 0 to 99.
OBD-II scanners typically provide descriptions of DTC meanings. More advanced models offer more detailed information. Online resources like Google can also be helpful in deciphering the meaning of specific DTCs. It’s important to remember there are thousands of potential DTCs, but not all indicate critical issues. Some may simply alert you to minor problems like slightly elevated engine temperature.
Choosing the Best OBD-II Scanner for Your Needs
Investing in one of the best OBD-II scanners is a smart way to gain insights into your vehicle’s operation and diagnose potential problems before they escalate. It’s the same technology used by dealerships and repair shops, putting diagnostic power directly in your hands.
When selecting an OBD-II scanner, consider these key factors:
Handheld vs. Wireless:
- Handheld OBD-II scanners feature an integrated screen and connect directly to your car’s OBD port via a cable.
- Wireless OBD-II scanners plug into the OBD port and communicate wirelessly via Bluetooth to a smartphone or tablet for data display.
Both types offer high-performance options under $200, with some basic models available for under $30. The ideal choice depends on your preferences and intended use.
Key Selection Criteria:
- Ease of Setup: A user-friendly setup process is crucial for convenient and frequent use.
- Fault Code Explanation: The best scanners not only display fault codes but also provide clear explanations, empowering you to understand the issue and decide on the appropriate action.
- I/M Readiness Check: Ensure the scanner can perform emissions and engine tests to verify inspection readiness.
- Accuracy: Reliable and accurate results are paramount for effective diagnostics.
- Size and Weight: A compact and lightweight scanner is more likely to be kept in your car for on-the-go diagnostics.
- Live Data Capability: Real-time data monitoring of engine parameters helps in diagnosing intermittent problems.
- Data Graphs: Visual data representation through graphs enhances understanding and comparison of readings.
- Warranty: Look for scanners with a solid warranty, ideally lifetime, to ensure long-term value.
Additional Features to Consider:
- Screen Size (Handheld): Opt for a large, bright, and easy-to-read display with intuitive icon-based navigation.
- Durability: Rugged scanners with rubber bumpers are more resistant to drops and workshop environments.
- Extra Features: Some scanners offer features like electrical multimeters, manufacturer-specific code reading, and PDF report export.
- Price: Balance features with your budget. Excellent OBD-II scanners are available at prices comparable to or less than an hour of mechanic labor.
Our OBD-II Scanner Testing Methodology
To rigorously evaluate OBD-II scanners, we conducted hands-on testing using a 2014 Audi A4 Allroad over several weeks in various driving conditions.
Testing Procedure:
- VIN Verification: Confirmed each scanner correctly identified the vehicle identification number (VIN).
- Connectivity: Tested wireless scanner connections (Bluetooth/Wi-Fi) with Apple iPad Pro, Microsoft Surface, and Samsung Galaxy S9+. Handheld scanners were tested via direct OBD-II port connection.
- Range Measurement: Measured cable length for handheld scanners and wireless range for Bluetooth models.
- Live Data Monitoring: Observed engine and vital system data while the car was running.
- Fault Code Generation & Reading: Disconnected the engine oil temperature sensor to trigger a fault code. Verified the scanner’s ability to accurately report and explain the code.
- Fault Code Clearing: Confirmed the scanner could successfully clear the fault code and turn off the check engine light after reconnecting the sensor.
- Road Testing: Evaluated live data display during actual driving conditions, noting data presentation (numbers, graphs, gauges).
Fault Code Interpretation:
We analyzed the fault codes generated by each scanner, understanding the structure of the four-number, letter-prefix codes:
- P (Powertrain), B (Body), C (Chassis), U (Undefined)
- Numeric section: Starting with 0 for generic codes and 1 for manufacturer-specific codes.
Our testing focused on assessing the accuracy, ease of use, features, and overall value of each OBD-II scanner to provide informed recommendations.
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