The best OBD-II scanners are essential tools for modern car owners, acting as a bridge to your car’s onboard computer and unlocking a wealth of diagnostic information. Whether you’re facing a mysterious dashboard light or suspect a deeper issue, these scanners empower you to understand your vehicle’s health without immediately resorting to expensive professional diagnostics.
Navigating the world of OBD-II scanners can be daunting, especially for beginners. The market offers a vast array of options, each with varying features and price points. Having tested numerous OBD-II scanners over the years, we’ve pinpointed the top contenders that deliver exceptional value and performance. Below, we’ll delve into our recommended OBD-II scanners, focusing on which offers the best features for your budget. We’ll also explain how OBD-II scanners function and demystify those cryptic error codes.
Among our top selections, the Topdon TopScan stands out as a remarkably user-friendly wireless option packed with diagnostic capabilities. For budget-conscious users, the Launch CR529, priced around $40, provides excellent value. If you’re seeking a more professional-grade experience, the Topdon Phoenix Lite 2 offers advanced features, albeit at a premium price of $799.
Here are our top picks for the best OBD-II scanners you can buy right now, balancing features and affordability.
Tom Pritchard
Tom is the UK Phones Editor for Tom’s Guide, evaluating everything from the latest smartphones to essential mobile applications. He is also a passionate advocate for electric vehicles.
The Quick List: Best OBD2 Code Readers for the Money
Based on our hands-on testing, here’s a quick rundown of the best OBD-II scanners available today. Continue scrolling for detailed reviews of each product and insights into their standout features.
1. Topdon TopScan – Best Mobile Scanner
This Bluetooth scanner is incredibly easy to set up and use, offering a suite of professional-level diagnostic features in a compact design. Expect comprehensive diagnostics, repair guidance, parts information, and even predictive analysis to anticipate potential issues.
Read more below
2. Launch CR529 – Best Cheap Scanner
The Launch CR529 is a small yet powerful OBD-II scanner that delivers essential diagnostic functions and some higher-end capabilities not typically found in its price range. Lifetime support and updates further enhance its value.
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3. Topdon Phoenix Lite 2 – Best Pro-level Scanner
With its robust, horizontal design reminiscent of a Nintendo Switch, the Topdon Phoenix Lite 2 is built for both professionals and serious DIYers. It’s a powerful, durable scanner ready for demanding use.
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4. Ancel BD310 – Best Dual-Purpose Scanner
The Ancel BD310 functions effectively as an OBD-II scanner and can also enhance your car’s dashboard by displaying various engine specifications. It combines simplicity, smartphone compatibility, and affordability.
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5. Carly OBD-II Scanner – Best Scanner with a Companion App
The Carly OBD-II Scanner’s utility is highly dependent on your vehicle’s make, with brands like VW, BMW, and Ford benefiting most from its features. It boasts one of the most comprehensive companion apps available, offering extensive customization and professional-grade testing.
What are the Best OBD-II Scanners for the Money? – Detailed Reviews
Why Trust Tom’s Guide? Our team rigorously tests and reviews products to provide unbiased recommendations, helping you choose the best for your needs. Learn more about our testing methodology.
Best Mobile OBD-II Scanner: Topdon TopScan
(Image credit: Topdon)
1. Topdon TopScan – Perfect for in-depth car diagnostics.
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:
- Exceptional automotive diagnostic coverage
- Displays live data streams
- Unique performance indicators
- Covers essential maintenance items
Reasons to Avoid:
- Bulky transmitter
- Subscription required for some features after the first year
The Topdon TopScan may appear unassuming, but this compact scanner is packed with features that go far beyond basic OBD-II diagnostics. More than just a standard Bluetooth OBD-II module that transmits data to your smartphone app, the TopScan surpasses many competitors in its class.
Beyond reading fault codes and performing I/M Readiness tests, the TopScan excels in performance and efficiency analysis. It can even estimate your car’s horsepower and torque – capabilities often missing in scanners costing ten times as much. Whether you’re aiming to optimize your car’s performance or ensure its roadworthiness, the TopScan is a valuable addition to any toolkit.
Read our full Topdon TopScan review
Best Cheap OBD-II Scanner: Launch CR529
(Image credit: Future)
2. Launch CR529 – A top OBD-II scanner under $50.
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 report generation
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 available. Its low price of around $38 belies the impressive range of diagnostic features it offers. The level of functionality for such a minimal investment is truly remarkable.
While compromises are expected at this price point, such as the absence of manufacturer-specific codes and a slightly hefty feel, the CR529 still provides essential features. It offers live data, instant inspection capabilities, and surprisingly detailed insights into your car’s systems. Furthermore, lifetime updates ensure long-term usability without subscription fees.
For users seeking professional-grade features, the CR529 might fall short. However, for the average car owner, it’s an excellent, budget-friendly tool to have on hand.
Read our full Launch CR529 review
Best Pro-Level OBD-II Scanner: Topdon Phoenix Lite 2
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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-1224700782076728613-20)
3. Topdon Phoenix Lite 2 – Bridging the gap between amateur and professional diagnostics.
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:
- Near-professional OBD scanner capabilities
- Versatile handheld with Wi-Fi and Bluetooth
- Large 8-inch touchscreen display
- Extensive suite of diagnostic tests and live data
- Includes adapters and a protective hard case
Reasons to Avoid:
- Large, heavy, and can feel cumbersome
- High price point
- Subscription required after two years for updates
The Topdon Phoenix Lite 2 is a significant investment compared to other OBD-II scanners, but it justifies its price with a wealth of features suitable for both experienced DIYers and professional mechanics. It offers a comprehensive diagnostic experience in a user-friendly package.
A standout feature is its wireless operation, with the control pad connecting via Bluetooth to a receiver plugged into the OBD port, allowing for greater mobility around the vehicle. While somewhat bulky and heavy, the scanner’s rugged design and built-in kickstand are ideal for workshop environments.
The Phoenix Lite 2 boasts advanced features like live data graphing, detailed fault information, and functionalities rarely found in budget scanners. However, note that firmware updates are only free for two years, after which a yearly subscription of $495 is required.
Read our full Topdon Phoenix 2 Lite review
Best Dual-Purpose OBD-II Scanner: Ancel BD310
Ancel BD310 (Image credit: Tom’s Guide)
4. Ancel BD310 – A versatile OBD-II scanner with added functionality.
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
- Functions as both a scanner and secondary car display
- Offers handheld and Bluetooth scanning options
Reasons to Avoid:
- Minimalist interface
- Small screen size
The Ancel BD310 is a dual-purpose scanner that operates as a standard handheld device and can connect to smartphones via Bluetooth. Uniquely, it can also function as a secondary display within your car, showing key engine metrics in real-time.
Its compact and lightweight design makes the BD310 exceptionally portable, easily fitting in a glovebox. The 2-inch screen is admittedly small, and the four-key interface may feel slightly awkward, but these aspects don’t hinder its diagnostic capabilities.
The 56-inch cable provides ample reach for under-hood work. The BD310 performs essential functions like I/M readiness tests and displays performance data, including coolant temperature, engine timing, and speed.
Read our full Ancel BD310 review.
Best Companion App: Carly OBD-II Scanner
(Image credit: Carly)
5. Carly OBD-II Scanner – Scanner performance is car-dependent, app is universally excellent.
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
- Covers maintenance and repair functions
- Lifetime warranty and updates
Reasons to Avoid:
- Feature availability varies by car model
- App subscription can be costly
The Carly OBD Scanner offers a wealth of features, with its companion app being a standout aspect. Unlike basic apps accompanying many Bluetooth scanners, Carly’s app is exceptionally well-designed and feature-rich.
Beyond basic diagnostics and fault code clearing, the app provides repair assistance and tools for pre-purchase used car inspections. The lifetime warranty is a significant advantage, offering long-term peace of mind.
However, the functionality of the Carly scanner is car-dependent; not all features work with every make and model. Compatibility should be verified before purchase. Furthermore, accessing advanced features beyond basic OBD functions requires an ongoing subscription, which can add to the overall cost.
Read our full Carly OBD scanner review
Other OBD-II Scanners We’ve Tested
Innova CarScan Mobile 1000 (★★★★☆)
The Innova CarScan Mobile 1000 is a highly innovative Bluetooth OBD-II scanner, integrating Innova’s impressive features like predictive diagnostics in a wireless, phone-based format. Its remarkably simple setup process further enhances its appeal as a Bluetooth-only option.
Read the full Innova CarScan Mobile 1000 review
ThinkCar ThinkDiag TKD01 (★★★★☆)
While larger than typical Bluetooth OBD-II scanners, the ThinkCar ThinkDiag TKD01’s size contributes to its durability. It offers extensive manufacturer-specific error codes and advanced fault-code analysis capable of resolving minor issues without professional intervention. 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 excels in diagnosing electrical problems, thanks to its integrated multimeter. It can identify issues like damaged wiring, short circuits, and blown fuses. It also provides a wide range of 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 diagnose car problems using diagnostic scanners plugged into the OBD port to access the onboard computer’s information, not by manual disassembly. OBD-II scanners, at their most basic, read and identify error codes flagged by your car when it detects an issue. Advanced models monitor systems in real-time and predict potential problems.
What is the OBD-II Port?
The On-Board Diagnostics Version Two (OBD-II) port is standard on most passenger vehicles sold in the U.S. since 1996, Canada since 1998, EU since 2004, and Australia, Mexico, and New Zealand since 2006. It’s the interface port for accessing the onboard computer, used by OBD-II scanners, insurance black boxes, and dash cams. If you need help locating it, here’s a guide to find your car’s OBD-II port for North American vehicles and worldwide OBD-II/EOBD port locations.
What is a DTC?
DTC stands for Diagnostic Trouble Code, an error code generated by a car’s OBD system when it detects a problem. These codes are read by OBD-II scanners, enabling users to diagnose car issues. Standardized DTC codes are common across vehicle makes and models, but some manufacturers use unique DTCs specific to their vehicles.
What Do DTCs Actually Mean?
DTCs may seem like random characters, but they follow a logical structure to indicate the type of error. The first letter designates the affected system: Powertrain (P), Body (B), Chassis (C), or Network (N). The second character, a number, indicates if it’s a generic code (0) or manufacturer-specific code (1).
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
- 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 pinpoint the exact fault, ranging from 0 to 99. OBD-II scanners translate these codes, with advanced models providing more detail. While many resources like Google can help decipher DTCs, remember there are over 5,000 potential codes. Not all DTCs indicate critical issues; some may simply warn of minor problems like slightly elevated engine temperature.
How to Choose the Best OBD-II Scanner for You
Using one of the best OBD-II scanners is the most effective way to understand your vehicle’s condition or diagnose problems. It’s the same method dealerships and repair shops use. Why not have access to this information yourself? OBD-II scanners come in two main types:
Handheld OBD-II scanners include a screen and cable, connecting directly to the car’s OBD port. Wireless OBD2II scanners plug into the port and connect to smartphones or tablets via Bluetooth to display data.
High-quality OBD-II scanners are available for under $200, with some costing less than $30. Key features to consider for the best OBD-II scanner include size, weight, and the ability to accurately read fault codes and live data. Essential criteria are:
- Easy Setup: Quick setup is crucial for timely diagnostics.
- Faults and Explanations: Scanners should identify faults and explain their meanings for DIY repairs or mechanic communication.
- I/M Readiness Check: Checks major engine and emissions systems for state inspection readiness.
- Accuracy: Reliable results are paramount; inaccurate data is worse than no data.
- Size and Weight: Portability ensures the scanner is available when needed, not just in the toolbox.
- Live Data: Real-time monitoring of engine parameters helps diagnose intermittent issues.
- Graphs: Visual data representation enhances analysis, especially for before-and-after comparisons.
- Warranty: Aim for scanners with long warranties, ideally lifetime, reflecting vehicle ownership duration.
Choosing between Bluetooth or handheld scanners is the first step. Consider longevity with lifetime warranties or software updates to keep pace with automotive technology. For handheld scanners, prioritize screen size and clarity with icon-based interfaces. Rugged models with bumpers are beneficial for durability. Extra features like multimeters, manufacturer-specific code reading, or PDF export capabilities add value. The affordability of sophisticated scanners, often under $100, makes them a cost-effective alternative to professional diagnostic labor.
How We Test OBD-II Scanners
To evaluate OBD2 scanners, we used a 2014 Audi A4 Allroad over several weeks in various conditions. Each scanner was connected to the 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 powered directly through the OBD-II port.
Cord length (for handhelds) and wireless range were measured. With the engine running, engine and vital systems were monitored before simulating a fault by disconnecting the oil temperature sensor. Scanner details were assessed, the issue was resolved, the check engine light cleared, and error codes erased.
Road tests then evaluated live operating data display, such as engine speed, timing, and coolant temperature, noting data presentation as numbers, graphs, or gauges. Understanding fault codes is crucial; they consist of a letter prefix and four numbers:
- Powertrain (P)
- Body (B)
- Chassis (C)
- Undefined (U)
Of approximately 5,000 diagnostic codes, generic codes (starting with 0) apply universally (e.g., air temperature, throttle position). Manufacturer-specific codes (starting with 1) relate to unique hardware or in-depth problem analysis. For example, P0098 indicates an intake air temperature sensor issue, while Ford’s P1112 (specialty code) suggests intermittent intake air temperature sensor values requiring replacement.
