The Best Obd-ii Scanners are essential tools for modern car owners. They act as a bridge to your car’s onboard computer, unlocking a wealth of information about its health and performance. Whether you’re facing a mysterious dashboard light or just want to understand your vehicle better, an OBD-II scanner allows you to diagnose problems like a professional, all without the hefty mechanic fees.
However, the world of OBD-II scanners can be overwhelming, especially for beginners. The market is flooded with options, each promising to be the “best.” Having tested numerous OBD-II scanners over the years, we’ve cut through the noise to bring you a curated list of the top performers. Below, we’ll delve into our recommended scanners, explain how OBD-II scanners work, and demystify those confusing error codes.
Among our top selections, the Topdon TopScan stands out as a remarkably user-friendly wireless option packed with diagnostic power. For budget-conscious users, the Launch CR529, priced around $40, offers incredible value. If you’re seeking a professional-grade experience, the Topdon Phoenix Lite 2 delivers advanced diagnostics, though it comes with a premium price tag of $799.
Here’s a quick rundown of the best OBD-II scanners available today:
Tom Pritchard
Tom is the UK Phones Editor at Tom’s Guide, covering everything mobile tech, from the latest smartphones to essential apps. A passionate advocate for electric vehicles, he’s always ready to champion their merits.
Top OBD-II Scanners: Quick List
These are our top recommendations for the best OBD-II scanners you can buy right now, based on extensive hands-on testing. Keep scrolling for detailed reviews of each scanner and why they earned a spot on our list.
Topdon TopScan: Best Mobile OBD-II Scanner
1. Topdon TopScan: Best Mobile OBD-II Scanner
This Bluetooth scanner impressed us with its easy setup and professional-grade features, all within a compact design. It offers comprehensive diagnostics, repair guidance, parts lists, and even predictive analysis to anticipate potential issues.
Dive Deeper into Topdon TopScan
Launch CR529: Best Cheap OBD-II Scanner
2. Launch CR529: Best Budget-Friendly OBD-II Scanner
The Launch CR529 is a small but mighty scanner that provides all the essential OBD-II functions, plus some advanced features typically found in higher-priced models. Lifetime support and updates add to its exceptional value.
Explore the Launch CR529 in Detail
Topdon Phoenix Lite 2: Best Pro-Level OBD-II Scanner
3. Topdon Phoenix Lite 2: Best Professional-Grade OBD-II Scanner
Resembling a rugged tablet, the Topdon Phoenix Lite 2 is built for both professionals and serious DIYers. It’s a robust device packed with powerful features for in-depth diagnostics.
Learn More About the Topdon Phoenix Lite 2
Ancel BD310: Best Dual-Purpose OBD-II Scanner
4. Ancel BD310: Best Versatile OBD-II Scanner
The Ancel BD310 functions not only as an OBD-II scanner but also as an auxiliary display for your car, showing real-time engine data. Its sleek design, smartphone compatibility, and affordable price make it a great choice.
Discover the Ancel BD310’s Dual Functionality
Carly OBD-II Scanner: Best OBD-II Scanner with Companion App
5. Carly OBD-II Scanner: Best OBD-II Scanner with Companion App
The Carly Scanner’s value is highly dependent on your car make, with brands like VW, BMW, and Ford benefiting most from its features. However, its standout feature is its exceptional companion app, offering extensive customization and professional-level tests.
Explore the Carly OBD-II Scanner App Experience
Deep Dive: The Best OBD-II Scanners in Detail
Why Trust Tom’s Guide? At Tom’s Guide, our team of expert writers and editors dedicates countless hours to rigorously testing and reviewing products, services, and apps. Our goal is to provide you with unbiased and thorough recommendations to help you make the best choices. Learn more about our rigorous testing process.
1. Topdon TopScan: Best Mobile OBD-II Scanner
(Image credit: Topdon)
Topdon TopScan – Perfect for Unlocking Your Car’s Hidden Potential
Read our 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 (touchscreen via app)
- Warranty: 2 years
- Dimensions: 3.2 x 2.0 x 1.1 inches
- Weight: 2.6 ounces
Reasons to Buy:
- Exceptional Automotive Diagnostic Coverage: Offers in-depth diagnostics across a wide range of vehicle systems.
- Real-time Live Data: Provides crucial live data streams for monitoring vehicle performance.
- Unique Performance Indicators: Goes beyond basic diagnostics to assess performance metrics.
- Comprehensive Maintenance Features: Covers essential maintenance aspects for proactive car care.
Reasons to Avoid:
- Bulky Transmitter: The Bluetooth transmitter module is larger than some competitors.
- Subscription for Full Features: Some advanced features require a subscription after the initial year.
Don’t let its unassuming appearance fool you – the Topdon TopScan is a powerhouse in a small package. This isn’t just another basic Bluetooth OBD-II adapter; it’s a sophisticated diagnostic tool that significantly surpasses many scanners in its class. We were particularly impressed by its ability to delve into performance and efficiency metrics, far beyond simply reading fault codes and running I/M readiness tests. The TopScan can even estimate your car’s horsepower and torque, features rarely found even in scanners costing ten times as much. Whether you’re a performance enthusiast looking to fine-tune your vehicle or simply want to ensure its long-term health and roadworthiness, the Topdon TopScan is an invaluable addition to your toolkit.
Read our comprehensive Topdon TopScan Review
2. Launch CR529: Best Cheap OBD-II Scanner
(Image credit: Future)
Launch CR529 – Unbeatable Value for Under $50
Read our Expert Review
Key Specifications:
- Display: 2.8-inch Color Screen
- Connectivity: Wired (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: Incredibly priced, making OBD-II diagnostics accessible to everyone.
- Lifetime Free Updates: Ensures your scanner remains up-to-date with the latest vehicle protocols and features.
- Easy Pre-Inspection Readiness Report: Simplifies emissions testing preparation.
Reasons to Avoid:
- Lacks Manufacturer-Specific Codes: May not access advanced diagnostic codes specific to certain car brands.
- Feels Heavy: Slightly heavier than some handheld scanners.
- Limited 1-Year Warranty: Warranty period is shorter compared to some competitors.
The Launch CR529 redefines “value” in the OBD-II scanner market. For its remarkably low price (around $38), it delivers a level of diagnostic capability that’s truly surprising. We were genuinely impressed by the features packed into such an affordable device. While some compromises are expected at this price point, such as the absence of manufacturer-specific codes and a slightly heavier feel, the CR529 still offers a wealth of functionality. You get live data streaming, a convenient instant inspection feature, and a surprisingly detailed view into your car’s internal systems. The inclusion of lifetime free updates is a significant bonus, ensuring long-term usability without subscription fees. While the CR529 might not satisfy professional mechanics seeking advanced features, it’s an exceptional choice for everyday car owners and DIY enthusiasts who want a reliable and budget-friendly diagnostic tool.
Read our in-depth Launch CR529 Review
3. Topdon Phoenix Lite 2: Best Pro-Level OBD-II Scanner
(Image credit: Future)
Topdon Phoenix Lite 2 – Bridging the Gap Between DIY and Professional Diagnostics
Read our Expert Review
Key Specifications:
- Display: 8-inch Color Touchscreen
- Connectivity: Bluetooth, Wi-Fi
- Handheld: Yes (Tablet-style)
- 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:
- Near-Professional OBD Scanner Capabilities: Offers advanced diagnostics approaching professional-grade tools.
- Versatile Handheld with Wi-Fi and Bluetooth: Combines handheld convenience with wireless connectivity.
- Large 8-inch Touchscreen: Provides a spacious and user-friendly interface.
- Extensive Diagnostic Tests and Live Data: Delivers a wide array of diagnostic functions and real-time data streams.
- Includes Adapters and Hard Case: Comes with necessary accessories and protective storage.
Reasons to Avoid:
- Bulky and Heavy: Larger and heavier than typical handheld scanners.
- Expensive Initial Investment: Higher price point compared to many OBD-II scanners.
- Subscription Required After 2 Years: Firmware updates and advanced features require a paid subscription after the initial two years.
The Topdon Phoenix Lite 2 commands a higher price than many OBD-II scanners, but it justifies the investment with a feature set that blurs the lines between amateur and professional diagnostic tools. You get an impressive array of capabilities that cater to both serious DIYers and professional mechanics. A standout feature is its wireless operation – the control tablet connects via Bluetooth to a receiver plugged into your car’s OBD port, providing unparalleled 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 designed to withstand demanding workshop environments. Beyond basic fault code reading, the Phoenix Lite 2 offers advanced features like live data graphing, in-depth fault information, and much more. However, be mindful of the subscription model – after two years, continued access to firmware updates requires an annual fee of $495.
Read our comprehensive Topdon Phoenix Lite 2 Review
4. Ancel BD310: Best Dual-Purpose OBD-II Scanner
(Ancel BD310 Image credit: Tom’s Guide)
Ancel BD310 – A Versatile Scanner That Does Double Duty
Read our Expert Review
Key Specifications:
- Display: 2-inch Color Screen
- Connectivity: Bluetooth, Wired (Handheld)
- 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 Compact: Easy to store and keep in your vehicle for on-the-go diagnostics.
- Dual Functionality: Works as both a standard scanner and a secondary car display.
- Handheld and Bluetooth Scanning: Offers flexible connectivity options.
Reasons to Avoid:
- Minimalist Interface: Interface design is very basic and may lack visual appeal.
- Small Screen: The 2-inch display can feel cramped for viewing data.
The Ancel BD310 stands out with its dual-purpose design, functioning as both a traditional handheld OBD-II scanner and a Bluetooth-connected auxiliary display for your car. When paired with a smartphone, it can display real-time engine parameters directly in your cabin. Its compact and lightweight design is a major advantage – it’s easily small enough to keep in your glovebox for convenient access whenever you need it. While the 2-inch screen is on the smaller side, and the four-button interface is somewhat basic, these design choices contribute to its portability without hindering its diagnostic capabilities. The 56-inch cable provides ample reach for comfortable use while working under the hood. The BD310 performs essential OBD-II functions like I/M readiness tests and provides access to performance data including coolant temperature, engine timing, and engine speed.
Read our full Ancel BD310 Review
5. Carly OBD-II Scanner: Best OBD-II Scanner with Companion App
(Image credit: Carly)
Carly OBD-II Scanner – Unlocking Features Through a Powerful App, Car Dependent
Read our Expert Review
Key Specifications:
- Display: None (relies on smartphone app)
- Connectivity: Bluetooth
- Handheld: No
- I/M Readiness Test: No
- Live Data Display: Yes
- Keys: None (touchscreen via app)
- Warranty: Lifetime
- Dimensions: 2.9 x 1.5 x 0.7 inches
- Weight: 0.7 ounces
Reasons to Buy:
- User-Friendly Interface: The companion app boasts an intuitive and easy-to-navigate interface.
- Extensive Customization Options: Offers a wide range of customizable features and settings within the app.
- Live Data Display: Provides real-time vehicle data monitoring.
- Maintenance and Repair Guidance: Offers helpful information for vehicle maintenance and repairs.
- Lifetime Warranty and Updates: Provides long-term support and feature enhancements.
Reasons to Avoid:
- Car Model Dependent Functionality: Feature availability varies significantly depending on your car’s make and model.
- App Subscription Costs: Access to advanced features beyond basic OBD-II functions requires an ongoing subscription, which can become expensive.
The Carly OBD Scanner stands out primarily for its exceptional companion app. While many Bluetooth OBD-II scanners offer basic app functionality, Carly delivers one of the most polished and feature-rich app experiences we’ve encountered. Beyond standard fault code reading and clearing, the app offers repair assistance, used car check tools (to identify potential “lemons”), and extensive customization options. The lifetime warranty is a rare and valuable offering, providing long-term peace of mind. However, the Carly’s effectiveness is heavily reliant on your specific car model. Certain features are limited or unavailable for some makes and models, so compatibility should be carefully verified before purchasing. Furthermore, unlocking the full potential of the Carly app beyond basic OBD-II functions requires a recurring subscription, which can add up over time.
Read our detailed Carly OBD scanner Review
Other OBD-II Scanners We’ve Tested
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Innova CarScan Mobile 1000 (★★★★☆) – One of the most innovative Bluetooth OBD-II scanners, inheriting Innova’s impressive features like predictive diagnostics in a wireless format. Its incredibly simple setup process makes it a standout Bluetooth-only option. Read the full Innova CarScan Mobile 1000 review
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ThinkCar ThinkDiag TKD01 (★★★★☆) – While larger than typical Bluetooth OBD-II scanners, its robust build makes the TKD01 virtually indestructible. Benefits include a wide array of manufacturer-specific error codes and extended fault codes capable of resolving minor issues without mechanic intervention. A $40 subscription is required after the first year. Read our full ThinkCar ThinkDiag TKD01 review.
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Autel AutoLink AL539 (★★★☆☆) – Specifically designed for diagnosing electrical problems, this OBD-II scanner incorporates a built-in multimeter. It excels at identifying issues like burnt wires, electrical shorts, and blown fuses. It also offers comprehensive 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?
Ever wondered how mechanics quickly pinpoint car problems? They don’t dismantle the engine piece by piece. Instead, they use diagnostic scanners that plug into your car’s OBD port, accessing data from the onboard computer. At their core, OBD-II scanners read and interpret error codes generated by your car when it detects an issue. More advanced scanners go further, monitoring systems in real-time and even predicting potential future problems. Think of an OBD-II scanner as your car’s translator, turning complex computer data into understandable information.
What is the OBD-II Port?
The On-Board Diagnostics Version Two (OBD-II) port is a standardized port found in nearly all passenger vehicles sold in the United States since 1996, Canada since 1998, the European Union since 2004, and Australia, Mexico, and New Zealand since 2006. This port is the universal access point to your car’s onboard computer. Besides OBD-II scanners, other devices like insurance black boxes and dash cams can also utilize this port. Unsure where your OBD-II port is located? Find your car’s OBD-II port location for North American vehicles. For worldwide locations, find your OBD-II/EOBD port here.
What Does DTC Stand For?
DTC stands for Diagnostic Trouble Code. These are the error codes generated by your car’s OBD system when it detects a malfunction. OBD-II scanners read these DTCs, allowing users to diagnose vehicle problems. While many DTCs are standardized across car makes and models, some manufacturers use proprietary DTCs specific to their vehicles.
Decoding DTCs: What Do They Actually Mean?
DTCs can seem like random alphanumeric strings, but they follow a logical structure that reveals the nature of the detected error. The first letter indicates the affected vehicle system:
- P: Powertrain (engine, transmission)
- B: Body (interior, comfort, safety systems)
- C: Chassis (brakes, suspension, steering)
- N: Network (communication systems)
The second character is a number: 0 for a generic code (standard across manufacturers) and 1 for a manufacturer-specific code. The third character pinpoints the specific subsystem experiencing the issue:
- 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 systems
- 6: Computer auxiliary outputs
- 7, 8, 9: Transmission and gearbox faults
- A, B, C: Hybrid-specific propulsion faults
The fourth and fifth characters further specify the fault, ranging from 0 to 99. OBD-II scanners translate these codes into plain English descriptions. More advanced scanners provide even more detailed information. While you can search online for DTC definitions, remember there are over 5,000 possible DTCs. Importantly, not all DTCs indicate critical problems. Some may simply signal minor issues like a slightly elevated engine temperature.
Choosing the Best OBD-II Scanner: Key Considerations
When seeking insights into your vehicle’s operation or diagnosing a problem, an OBD-II scanner is an invaluable tool. It provides access to the same diagnostic information used by dealerships and repair shops. Why not have this capability yourself? It’s important to understand that not all OBD-II scanners are created equal. There are two main types:
- Handheld OBD-II Scanners: These come with an integrated screen and a cable for direct connection to your car’s OBD port.
- Wireless OBD-II Scanners: These plug into the OBD port and communicate wirelessly via Bluetooth to a smartphone or tablet for displaying data.
Both types offer high-performance options under $200, with some excellent choices even under $30. The best OBD-II scanner for you will strike the right balance of size, features, and ease of use. Here are the crucial factors to consider:
- Easy Setup: A scanner that’s quick and straightforward to set up encourages regular use for early problem detection.
- Fault Codes and Explanations: The best scanners not only display fault codes but also provide clear explanations, enabling DIY repairs or informed communication with mechanics.
- I/M Readiness Check: A valuable feature for emissions testing, allowing you to verify your vehicle’s readiness.
- Accuracy: Reliable and accurate results are paramount for effective diagnostics. Inaccurate information is worse than no information at all.
- Size and Weight: A compact and lightweight scanner is more likely to be kept in your car for convenient roadside diagnostics.
- Live Data: Access to real-time engine data (speed, timing, etc.) is essential for diagnosing intermittent issues.
- Data Graphs: Visual data representation through graphs enhances understanding, especially for comparative analysis.
- Warranty: Consider scanners with long warranties, ideally lifetime warranties and software updates to ensure long-term value and compatibility with evolving automotive technology.
When choosing, first decide between a handheld scanner with its own display or a wireless scanner that uses your phone or tablet. Next, prioritize longevity with scanners offering lifetime warranties or software updates. For handheld scanners, opt for the largest, clearest, and most readable screen with an intuitive icon-based interface. If durability is a concern, consider ruggedized scanners with shock-absorbing bumpers. Look for bonus features like electrical multimeters, manufacturer-specific code access, or PDF report export capabilities. Ultimately, sophisticated OBD-II scanners are available at surprisingly affordable prices, often under $100 – a fraction of the cost of a single hour of mechanic labor, making them a smart investment.
Our OBD-II Scanner Testing Methodology
To rigorously evaluate the best OBD2 scanners, I utilized my 2014 Audi A4 Allroad over several weeks, both in the garage and on the road. For each scanner, the first step was verifying its ability to correctly identify the car’s Vehicle Identification Number (VIN) after connecting to the OBD-II port. Wireless scanners were paired with an Apple iPad Pro, Microsoft Surface, or Samsung Galaxy S9+ via Bluetooth or Wi-Fi. Handheld scanners were powered directly through the OBD-II port connection.
Cord length was measured on handheld scanners, and wireless range was assessed for wireless models. With the engine running, I monitored engine performance and vital systems. To simulate a fault condition, I intentionally disconnected the engine’s oil temperature sensor. I then assessed the detail and accuracy of the fault information provided by each scanner. Afterwards, I reconnected the sensor, cleared the check engine light, and erased the error code using the scanner. Finally, I conducted on-road testing to evaluate each scanner’s ability to display real-time operating data such as engine speed, timing, and coolant temperature, noting whether data was presented numerically, graphically, or as simulated gauges.
Understanding fault codes is key to effective OBD-II scanner use. All fault codes consist of four numbers preceded by a letter:
- P (Powertrain)
- B (Body)
- C (Chassis)
- U (Undefined/Network)
Of the approximately 5,000 possible diagnostic fault codes, some are generic and apply universally across vehicles (e.g., air temperature, throttle position). These generic codes typically begin with a ‘0’ in the numeric section. Manufacturer-specific codes, starting with a ‘1’, are tailored to particular carmakers and often indicate specialized components or more detailed problem analysis. For example, a P0098 code generally points to an issue with the engine’s intake air temperature sensor. In contrast, a Ford-specific P1112 code indicates an intermittent issue with the intake air temperature sensor, suggesting replacement.
