The check engine light is on, and a wave of anxiety washes over you. Is it a minor issue, or something that’s going to cost a fortune at the repair shop? Before you panic, know that you can take control and understand your car’s health yourself. The secret weapon? An OBD-II scanner. These clever devices plug into your car’s computer, unlocking a wealth of information about its inner workings. But with so many options available, finding the best OBD scanner to buy can feel overwhelming.
Don’t worry, you’re not alone. Many car owners, from seasoned DIYers to complete beginners, feel lost in the world of automotive diagnostics. We’ve spent years testing and evaluating OBD-II scanners of all types, so we know exactly which ones are worth your money. Whether you’re seeking a basic code reader or a professional-grade diagnostic tool, we’ve got you covered.
Below, we’ll guide you through our top recommendations for the best OBD-II scanners currently on the market. We’ll also break down how these scanners work and demystify those confusing error codes.
Our top picks include the Topdon TopScan, a wireless marvel that packs impressive diagnostic power into a portable design. For budget-conscious users, the Launch CR529 offers exceptional value without sacrificing essential features. And if you’re looking for a professional-level experience, the Topdon Phoenix Lite 2 delivers advanced diagnostics comparable to what you’d find in a mechanic’s garage.
Here’s a quick look at the best OBD-II scanners you can buy right now, based on our rigorous hands-on testing.
Tom Pritchard
Tom is the UK Phones Editor for Tom’s Guide, covering everything mobile tech and also indulging his passion for electric vehicles.
The Quick List: Top OBD-II Scanners at a Glance
For those in a hurry, here’s a quick rundown of our top OBD-II scanner recommendations. Scroll down for detailed reviews and buying advice.
1. Topdon TopScan: Best Mobile OBD-II Scanner
The Topdon TopScan stands out as the easiest Bluetooth scanner to set up and use. Despite its compact size, it offers a suite of professional-grade features, including comprehensive diagnostics, repair guidance, parts information, and even predictive analysis to anticipate potential issues.
Read more about the Topdon TopScan
2. Launch CR529: Best Cheap OBD-II Scanner
The Launch CR529 is a small but mighty OBD-II scanner that provides all the essential diagnostic functions you need, along with some higher-end features not typically found in its price range. Lifetime support and updates add to its exceptional value.
Explore the Launch CR529 in detail
3. Topdon Phoenix Lite 2: Best Pro-Level OBD-II Scanner
Resembling a rugged handheld console, the Topdon Phoenix Lite 2 is designed for both professionals and serious DIYers. It’s a robust and powerful scanner offering advanced features and comprehensive diagnostics for in-depth car analysis.
Discover the power of the Topdon Phoenix Lite 2
4. Ancel BD310: Best Dual-Purpose OBD-II Scanner
The Ancel BD310 is a versatile tool that functions as both a standard OBD-II scanner and an auxiliary dashboard display. Its compact design, smartphone compatibility, and reasonable price make it a great all-around option.
Learn more about the Ancel BD310’s dual functionality
5. Carly OBD-II Scanner: Best Scanner with a Companion App
The Carly OBD-II Scanner’s value is heavily dependent on your car make, with brands like VW, BMW, and Ford benefiting most from its extensive features. Its standout feature is its user-friendly and feature-rich companion app, offering customization and professional-level tests.
Explore the Carly OBD-II Scanner and its app
Detailed Reviews: Finding the Best OBD Scanner for Your Needs
Why Trust Tom’s Guide? Our team dedicates significant time to hands-on testing and in-depth reviews of products to provide you with the best recommendations. Learn more about our rigorous testing process.
1. Topdon TopScan: Best Mobile OBD-II Scanner
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(Image credit: Topdon)
Perfect for in-depth car diagnostics on the go.
Read our expert Topdon TopScan review
Specifications:
- Display/Size: None (App-based)
- Bluetooth/Handheld: Yes/No
- I/M Readiness Test: Yes
- Displays Live Data: Yes
- Number of Keys: None (App-controlled)
- Warranty: 2 years
- Size: 3.2 x 2.0 x 1.1 inches
- Weight: 2.6 ounces
Reasons to Buy:
- Excellent vehicle coverage for comprehensive diagnostics
- Real-time live data monitoring
- Unique performance indicators and tests
- Maintenance item coverage and reset functions
Reasons to Avoid:
- The Bluetooth transmitter module is somewhat large
- Advanced features may require a subscription after the first year
The Topdon TopScan may look unassuming, but this compact Bluetooth OBD-II scanner is a powerhouse of diagnostic capabilities. It’s more than just a basic module that sends data to your phone app; it goes above and beyond typical scanners in its class. We were impressed by its ability to delve deep into your car’s systems.
Beyond reading fault codes and performing I/M Readiness tests, the TopScan excels at performance and efficiency analysis. It can even estimate your car’s horsepower and torque, features often found in scanners costing ten times as much. Whether you want to fine-tune your vehicle’s performance or ensure it’s in top roadworthy condition, the Topdon TopScan is an invaluable tool to have in your arsenal.
Read our full Topdon TopScan review for a complete analysis.
2. Launch CR529: Best Cheap OBD-II Scanner
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(Image credit: Future)
The best OBD-II scanner for under $50, offering incredible value.
See our expert Launch CR529 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:
- Extremely affordable
- Lifetime free updates
- Easy pre-inspection report generation
Reasons to Avoid:
- Does not support manufacturer-specific codes
- Feels somewhat heavy for its size
- Shorter 1-year warranty
For car owners seeking the best OBD scanner to buy without breaking the bank, the Launch CR529 is a top contender. Priced under $50, it delivers a surprising level of diagnostic capability for the money. We were impressed by how much functionality is packed into this budget-friendly device.
While there are some trade-offs at this price point, such as the lack of manufacturer-specific code support and a slightly heavier feel, the CR529 still provides essential features like live data, instant vehicle inspection reports, and a remarkably detailed view into your car’s systems. The inclusion of lifetime updates ensures this scanner remains useful for years to come, without any subscription fees.
The CR529 may not be ideal for professional mechanics needing advanced features and manufacturer-specific diagnostics. However, for the average car owner, it’s hard to find a better value proposition in an OBD-II scanner.
Read our in-depth Launch CR529 review to learn more.
3. Topdon Phoenix Lite 2: Best Pro-Level OBD-II Scanner
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(Image credit: Future)
Bridging the gap between DIY and professional automotive diagnostics.
Explore our Topdon Phoenix Lite 2 expert review
Specifications:
- Display/Size: Color/8-inch Touchscreen
- Bluetooth/Handheld: Yes/Yes
- I/M Readiness Test: Yes
- Displays Live Data: Yes
- Number of Keys: Touchscreen interface
- 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
- Wireless operation with Bluetooth and Wi-Fi connectivity
- Large 8-inch color touchscreen display
- Extensive array of diagnostic tests and live data parameters
- Includes adapters and a protective hard case
Reasons to Avoid:
- Large, heavy, and can feel cumbersome
- Higher price point compared to basic scanners
- Subscription required for updates after two years
The Topdon Phoenix Lite 2 is a significant investment, costing considerably more than many other capable OBD-II scanners. However, it delivers a wealth of features and performance that justifies the price for serious DIYers and professional mechanics alike. You get a near-professional level diagnostic experience in a user-friendly package.
One of the standout features is its wireless operation. The tablet-like control pad connects via Bluetooth to a receiver plugged into your car’s OBD port, providing exceptional freedom of movement around the vehicle. While the scanner itself is substantial in size and weight, it features a built-in kickstand and rugged construction, making it suitable for demanding workshop environments.
The Phoenix Lite 2 offers advanced capabilities such as live data graphing, detailed fault code information, and many more features typically found only in high-end professional scan tools. Keep in mind that firmware updates are included for two years, after which a yearly subscription is required.
For a deeper dive, read our comprehensive Topdon Phoenix Lite 2 review.
4. Ancel BD310: Best Dual-Purpose OBD-II Scanner
Ancel BD310 (Image credit: Tom’s Guide)
A versatile OBD-II scanner that doubles as a car performance display.
See our expert Ancel BD310 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 a secondary car display
- Offers both handheld and Bluetooth scanning capabilities
Reasons to Avoid:
- User interface is quite minimalist
- Small 2-inch display screen
The Ancel BD310 is a unique dual-purpose OBD-II scanner that operates as a standard handheld device and can also connect to your smartphone via Bluetooth. Even more interestingly, it can transform into a secondary display, showing key engine parameters directly in your car’s cabin.
Its compact and lightweight design makes the BD310 incredibly portable; it easily fits in a glovebox. The 2-inch screen is admittedly small, and the four-button interface is somewhat basic, but it doesn’t hinder the scanner’s ability to diagnose car issues effectively.
The generous 56-inch cable is ideal for working under the hood, and the BD310 is capable of performing essential functions like I/M readiness tests and displaying performance data, including coolant temperature, engine timing, and RPM.
Read our full Ancel BD310 review for a detailed assessment.
5. Carly OBD-II Scanner: Best Scanner with a Companion App
(Image credit: Carly)
Check pricing on Carly’s Website
A feature-rich scanner, but its value depends on your car’s make.
Explore our Carly OBD scanner review
Specifications:
- Display/Size: None (App-based)
- Bluetooth/Handheld: Yes/No
- I/M Readiness Test: No
- Displays Live Data: Yes
- Number of Keys: None (App-controlled)
- Warranty: Lifetime
- Size: 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 and logging
- Maintenance and repair information within the app
- Lifetime warranty and software updates
Reasons to Avoid:
- Feature availability varies significantly by car model
- App subscription can become expensive for full functionality
The Carly OBD Scanner offers a compelling set of features, and its companion app is a standout element. Unlike many Bluetooth scanners with basic apps, Carly provides one of the most sophisticated and user-friendly app experiences we’ve encountered.
Beyond basic fault code reading and clearing, the Carly app offers repair guidance to help you get your car back on the road. It even includes pre-purchase used car checks to help identify potential problems before you buy. The lifetime warranty is a significant bonus, offering long-term peace of mind.
However, the Carly’s functionality is heavily car-dependent. Full feature access is primarily geared towards specific brands like VW, BMW, and Ford. Also, while the app is excellent, 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 to see if it’s the right fit for your car.
Other OBD-II Scanners We’ve Tested
While the above scanners are our top recommendations, we’ve tested several other models that are also worth considering:
- Innova CarScan Mobile 1000 (★★★★☆): This Bluetooth OBD-II scanner is packed with innovative features from Innova, including predictive diagnostics. Its wireless design and simple setup make it a great Bluetooth-only option. Read our Innova CarScan Mobile 1000 review. View Deal
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ThinkCar ThinkDiag TKD01 (★★★★☆): While larger than some Bluetooth scanners, the TKD01 is robust and durable. It offers extensive manufacturer-specific codes and advanced fault code analysis that can even resolve minor issues without mechanic intervention. A subscription is required after the first year. Read our ThinkCar ThinkDiag TKD01 review. View Deal
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Autel AutoLink AL539 (★★★☆☆): The Autel AutoLink AL539 excels at diagnosing electrical issues thanks to its integrated multimeter. It can identify problems like burnt wires, short circuits, and blown fuses. It also offers a wide range of live data and pre-inspection readiness checks. Read our Autel AutoLink AL539 review. View Deal
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 inspecting every component, these scanners connect to your car’s On-Board Diagnostics (OBD) port to access data from the onboard computer.
At their most basic, OBD-II scanners can read and interpret Diagnostic Trouble Codes (DTCs) – error codes generated by your car when it detects a problem. More advanced scanners can monitor vehicle systems in real-time, providing live data, and even predict potential future issues. Using an OBD-II scanner empowers you to diagnose car problems yourself, potentially saving money on mechanic fees and gaining valuable insight into your vehicle’s condition.
What is the OBD-II Port?
The OBD-II port is the standardized connector found in virtually all passenger vehicles sold in the United States since 1996, Canada since 1998, the European Union since 2004, and other regions like Australia, Mexico, and New Zealand since 2006.
This port serves as the interface point to your car’s onboard computer. Various devices can plug into the OBD-II port, including OBD-II scanners, insurance telematics devices, and even some dash cameras.
If you’re unsure of your OBD-II port’s location, you can find guides on locating your car’s OBD-II port for North American vehicles and worldwide OBD-II/EOBD port locations.
What is a DTC (Diagnostic Trouble Code)?
DTC stands for Diagnostic Trouble Code. These are error codes generated by your car’s OBD system when it detects a malfunction or issue. OBD-II scanners read these DTCs, allowing users to identify the source of a problem.
Many DTCs are standardized across different vehicle makes and models, but some manufacturers also 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 type of problem your car is experiencing.
The first character indicates the affected vehicle system:
- P – Powertrain (engine and transmission)
- B – Body (interior and exterior components)
- C – Chassis (braking, suspension, steering)
- N – Network (communication systems)
The second character is a number:
- 0 – Generic code (standardized across manufacturers)
- 1 – Manufacturer-specific code
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 controls and idle control
- 6 – Computer auxiliary outputs
- 7, 8, 9 – Transmission and gearbox faults
- A, B, C – Hybrid-specific propulsion faults
The fourth and fifth characters provide further detail about the specific fault and range from 0 to 99.
OBD-II scanners translate these codes into understandable descriptions. Advanced scanners offer more detailed information, but online resources like Google can also help you decipher DTCs. It’s important to note that there are thousands of possible DTCs, and not all indicate critical problems. Some may simply warn of minor issues like slightly elevated engine temperature.
How to Choose the Best OBD-II Scanner for You
If you want to understand your car’s health and diagnose issues yourself, an OBD-II scanner is an essential tool. It provides the same diagnostic information used by dealerships and repair shops, putting you in control.
When choosing the best OBD scanner to buy, consider these key factors:
Scanner Type:
- Handheld OBD-II Scanners: These come with an integrated screen and connect directly to your car’s OBD port via a cable. They are self-contained and easy to use.
- Wireless OBD-II Scanners: These plug into the OBD port and communicate wirelessly via Bluetooth or Wi-Fi to a smartphone or tablet for displaying data. They offer portability and app-based features.
Essential Criteria for the Best OBD-II Scanners:
- Easy Setup: A scanner should be quick and straightforward to set up so you can diagnose issues promptly.
- Fault Code Explanation: The best scanners not only display fault codes but also provide clear explanations of their meaning, helping you understand the problem and decide on the next steps (DIY repair or mechanic visit).
- I/M Readiness Check: A valuable feature for emissions testing, this function checks if your car will pass state inspections.
- Accuracy: Reliable and accurate diagnostic results are crucial. Incorrect information is worse than no information.
- Size and Weight: A compact and lightweight scanner is more convenient to store in your car and use on the go.
- Live Data: The ability to monitor real-time engine parameters (speed, timing, etc.) helps in diagnosing intermittent problems.
- Data Graphs: Visual representations of data (graphs) are often more insightful than raw numbers, especially for comparing data over time.
- Warranty and Updates: Look for scanners with a good warranty and software updates to ensure long-term usability and compatibility with newer vehicles. Lifetime warranties are a significant plus.
Additional Features to Consider:
- Screen Size (Handheld Scanners): Opt for a large, bright, and easy-to-read display with an intuitive icon-based interface.
- Ruggedness: If you work in demanding environments, consider a rugged scanner with rubber bumpers for added durability.
- Extra Features: Some scanners offer features like electrical multimeters, manufacturer-specific code reading, and PDF report export.
Price: You can find high-quality OBD-II scanners, even professional-level ones, for under $200. Some basic models are available for under $30. Considering the potential savings on mechanic diagnostic fees, an OBD-II scanner is a worthwhile investment.
How We Test OBD-II Scanners
To determine the best OBD-II scanners, we conduct hands-on testing over several weeks using a 2014 Audi A4 Allroad. Our testing process includes:
- VIN Verification: Ensuring each scanner correctly identifies the vehicle identification number (VIN).
- Connectivity Testing: For wireless scanners, we test Bluetooth and Wi-Fi connections with devices like Apple iPads, Microsoft Surface tablets, and Samsung Galaxy smartphones. Handheld scanners are tested for direct OBD port connection.
- Range and Cord Length: Measuring the wireless range of Bluetooth scanners and the cable length of handheld models.
- Live Data Monitoring: Monitoring engine and vital systems in real-time while the car is running.
- Fault Code Generation and Reading: Simulating a fault by disconnecting the engine oil temperature sensor to assess the scanner’s ability to detect, display, and explain fault codes.
- Fault Code Clearing: Verifying the scanner’s ability to clear fault codes and turn off the check engine light after resolving the simulated issue.
- Road Testing: Evaluating the scanner’s ability to display and graph real-time operating data (engine speed, timing, coolant temperature) during actual driving conditions.
- Data Presentation: Assessing how data is presented – as numbers, graphs, or gauges – and its clarity and usability.
Our testing rigorously evaluates each scanner’s ease of use, features, accuracy, and overall performance to provide you with reliable recommendations for choosing the best OBD scanner to buy.
More From Tom’s Guide
- Best Car Dash Cams
- Best Portable Car Jump Starters
- Best Car Phone Mounts
By investing in one of the best OBD-II scanners, you gain valuable insight into your car’s health and can confidently address issues, saving time and money in the long run. Choose the scanner that best fits your needs and budget, and empower yourself with the knowledge to keep your vehicle running smoothly.
