Our editors pick the products & services we write about. When you buy through our links, we may get a commission. Learn more.

Best FREE OBD2 software for Windows PC 2021 [Review]

With the right automotive diagnostic software, you can view more data—and do more with it—than you can with hand-held OBDII scanners. Depending on the software, you may even be able to perform advanced tuning and programming functions, all for a lot less than you’d pay for a professional diagnostic tool. 

There are many great software options out there, each of which is designed for a certain kind of user. Let’s take a look at our top 10, so you can pick the one that fits best with your vehicle. 

Best auto diagnostic software review

1. Toad Pro – best professional automotive diagnostic software

toad pro review
TOAD Pro Professional Automotive Diagnostic Software
TOAD Pro is a powerful piece of software for both DIYers and professionals.

Key Features and Functions

Toad Pro’s features start with full OBD2 diagnostics, including reading and clearing codes that trigger the check engine light, along with emissions testing and reading the live data stream. Also, it can check the transmission system, even codes that don’t come up through OBD2. All sensor data can be recorded and played back.

Its most impressive feature, though, is its ability to tune and remap ECU chips. The software comes with 14,000 optimized map files included and a map editor for custom tuning. If you want the option to optimize your engine’s performance, Toad Pro is one of the most comfortable and affordable ways to do it. 

You’ll get some helpful repair functions with Toad Pro, as well. These include DPF and EGR regeneration for diesel vehicles, along with “active tests” for actuators.

Vehicle Coverage

OBD Auto Doctor Professional Automotive Diagnostic Software is good idea for mechanics, service center, DIY enthusiasts, and home car owners
OBD Auto Doctor can help users in many special functions.

The broad coverage of Toad Pro includes the majority of vehicles on the road today. This includes all US vehicles made after 1996, Canadian vehicles made after 1998, European vehicles made after 2001, and Australian vehicles made after 2006. To confirm compatibility, you can reference the list on their website. 

Pricing & Updates

You’ll get lifetime support and updates for free once you install Toad Pro. The initial cost depends on which aspects of the software you need, but even the most robust version costs less than $150

Operating System Requirements

Toad Pro is built for Windows and won’t work on Apple devices. Its Windows compatibility includes all computers and tablets running XP, Vista, 7, 8, 8.1, or 10. 

Verdict: With tuning and remapping capabilities as well as OBD2 diagnostics, Toad Pro is a powerful piece of software for both DIYers and professionals. 

Check Price

2. OBD Auto Doctor – best OBD2 programming software

Key Features and Functions

You can read any trouble code with OBD Auto Doctor, including pending and permanent codes. Its data reading capabilities are equally robust, with support for more than 126 PIDs. This sensor data can be saved as a .csv file and graphed in programs like Excel or Google Sheets. 

Along with this, you’ll get a range of onboard monitor tests and activation functions. Running an EVAP leak test or DPF regeneration program is quick and easy. Since it also shows freeze frame data and performs 11 system tests, it’s an excellent option for troubleshooting a range of engine issues. 

The commercial version of OBD Auto Doctor is the most comprehensive. Its main helpful addition is the Troubleshoot Console. Designed for advanced users, this lets you send commands to the vehicle, enabling a wide range of repairs. 

Vehicle Coverage

OBD Auto Doctor works with both gas and diesel engines and supports all OBD2 protocols. 

Pricing & Updates

There are three levels of OBD Auto Doctor, ranging in price from $39.95 (for individuals) to $119.95 (for commercial use). Once you obtain a license, you’ll get free downloads of updates for the next year. Following that, you’ll get a discount if you’d like to purchase additional upgrades. 

Operating System Requirements

OBD Auto Doctor is one of the few diagnostic programs that will work with Windows, Mac, and Linux operating systems. 

Verdict: Broad operating system compatibility is the main strength of OBD Auto Doctor, which supports comprehensive auto diagnostics on Windows, Mac, or Linux devices. 

Download: https://www.obdautodoctor.com/tour

Read more: Get to Know Everything about OBD Auto Doctor Before Buying

3. VIEZU – best car tuning software

Key Features and Functions

Viezu is a comprehensive car tuning software that allows users to tune and remap their engines easily. Their primary offering is their K-Suite of software, which includes the programs Kess 3.0 and KTAG 3.0. Between them, they support a range of programming options, including manual ECU mapping, live tuning, 3D tuning, and more. 

One thing to keep in mind is that this is an advanced piece of software designed for experienced mechanics. While there is a function to restore vehicle defaults should you make a mistake, it’s not the best choice for beginning mechanics since you can potentially cause ECU errors. 

For professionals, though, the broad retuning capabilities of Viezu software make it one of the most potent options on the market. 

Vehicle Coverage

The K-Suite software can be used with both gas and diesel engines made in 1996 and later. This comprehensive vehicle support is one reason it’s such a powerful tool for professional mechanics. 

Pricing & Updates

Updates are free and automatic with Viezu K-Suite. If you’d like to revert to an older version, you can do so through the “Support” menu. 

Operating System Requirements

The Viezu software has a relatively limited operating software compatibility. It can be downloaded only on devices running Windows 8, 8.1, or 10.

Verdict: Viezu is one of the most potent and comprehensive tuning programs on the market, ideal for advanced mechanics who want the freedom to remap and retune vehicle ECUs entirely. 

Download: https://viezu.com/software

4. ScanXL Pro – best OBD2 diagnostic software

Key Features and Functions

ScanXL Pro is a comprehensive diagnostic software for reading trouble codes and viewing live data from various vehicle systems. Along with comprehensive OBDII diagnostics (over 220 parameters), you can also read the ABS and SRS systems and many proprietary manufacturer systems hand-held scanners don’t cover. 

Along with its diagnostic power, the Vehicle Manager and Virtual Dashboard features of ScanXL Pro are useful features. The Vehicle Manager lets you track all the information from a range of vehicles. New vehicles can be easily added through the built-in database. 

The Virtual Dashboards, meanwhile, are fully-customizable, allowing you to view a range of gauges and parameters (up to 8 per graph). These can be moved, resized, and configured to show you the exact data you need from your vehicle. 

Vehicle Coverage

For general OBD2 diagnostics, ScanXL Pro is compatible with any OBD2-compliant vehicle. This includes US vehicles made in 1996 or later.

Enhanced diagnostics (of ABS, SRS, and other systems) are more limited. Currently, ScanXL Pro supports GM, Mazda, Ford, Lincoln, and Mercury vehicles made from 1996-2009. You’ll also need to purchase an add-on package to get these functions. 

Pricing & Updates

The ScanXL Pro software is very affordable, costing less than $20 to download and install. The add-on for enhanced diagnostics is pricier, however, at the cost of $99.95 per manufacturer. Fortunately, you won’t need to pay to update once you’ve purchased the software, as updates come included in the cost. 

Operating System Requirements

You’ll need a Windows PC to use ScanXL Pro. It supports Windows XP, Vista, 7, and 2000.

Verdict: The diagnostic power and user-friendly interface of ScanXL Pro makes it the best diagnostic software for DIYers. 

Download: https://www.palmerperformance.com/products/scanxlpro/index.php

5. MaxxECU MTune – car tuning software

Key Features and Functions

The goal of MaxxECU MTune is to make software tuning simple. It does this with a user-friendly graphical interface that guides you through the process, making it one of the best intermediate DIYers options looking to get into chip tuning. 

MaxxECU MTune is feature-rich, too. It performs both 2D and 3D tuning and advanced functions like injector staging and removing speed limiters. You can also read real-time data from the engine with a single mouse click and diagnose faults, all in one handy piece of software. 

Vehicle Coverage

MaxxECU supports a wide range of vehicles, including familiar brands like Ford, Honda, Mazda, and more. You can see the full list of supported vehicles on their website if you want to make sure it will work with your vehicle. 

Pricing & Updates

MTune regularly releases free software updates to add features to the software and ensure it’s up to date. It will automatically search for new versions anytime you’re online, so finding and installing them is easy, too. 

Operating System Requirements

The MaxxECU software is designed for Windows and will work on any device running a Windows operating system. This includes both PCs and tablets, giving it more versatility in this regard than many tuning software packages. 

Verdict: The user-friendly design of MaxxECU MTune is why it’s our top recommendation for DIYers who want chip tuning software. 

Download: https://www.maxxecu.com/mtune

6. DashCommand – OBD2 Car Diagnostic Software

Key Features and Functions

The purpose of DashCommand is to integrate data monitoring and logging functions into your in-vehicle computing. Its customizable dashboard gives you easy access to the data and features you use most. 

With DashCommand, you can read and clear trouble codes and viewing and logging sensor, and monitor data. Its only significant lack compared to hand-held scanners is that it doesn’t view freeze frame data or show O2 sensor test results. 

The data logging functions are the heart of DashCommand. You can also customize what live data you see to keep track of the information that matters most for your vehicle. 

Vehicle Coverage

Complete support is one benefit of DashCommand. It can be used with any vehicle that uses OBD2 or EOBD protocols. So you can work on the majority of vehicles made and sold in North America and Europe. 

Pricing & Updates

DashCommand is affordable at around $40. Any firmware updates released are available through the Palmer Performance website and can be downloaded for free. 

Operating System Requirements

DashCommand is designed to be used with touchscreen displays, but it can also be used with mouse-and-keyboard navigation. It’s available for Windows operating systems, including Windows XP, Vista, 7, and 2000. Along with that, you can use it on iPads, iPhones, and Android-based touchscreen devices. 

Verdict: DashCommand is an affordable way to conduct basic OBDII diagnostics, with broad compatibility and a customizable interface that lets you tailor it to meet your needs. 

Download: https://www.palmerperformance.com/products/dashcommand/windows/index.php

7. FORScan – ELM327 auto computer software

Key Features and Functions

With FORScan, you’ll get all of an OBD2 code reader‘s features in a versatile software package. The FORScan Lite software allows you to read and clear trouble codes from any onboard module. Besides, it reads module sensor data and the vehicle’s network configuration. 

Upgrading to FORScan Pro expands this functionality. You can run diagnostic tests to find the source of any trouble codes. It also adds advanced configuration and programming functions and service functions like oil reset, SAS calibration, and DPF regeneration. 

Vehicle Coverage

FORScan is compatible with Ford, Lincoln, Mercury, and Mazda vehicles made in 1996 or later. The only gaps in this coverage are the Mazda 3 and CX-30 vehicles made after 2019. This tight focus on a few manufacturers lets it provide the specific features those owners need at an affordable price. 

Pricing & Updates

The standard version of FORScan is free to download and use. Even upgrading to the Pro version is remarkably affordable, at just $10. The software is regularly updated, and you can view the most recent updates on the FORScan site. These updates will install automatically.

Operating System Requirements

FORScan is available for a range of operating systems. This includes iOS 7.0 and higher, Android 4.0 and higher, Windows XP, Vista, 2000, 7, 8, 8.1, and 10. 

Verdict: FORScan is the most affordable way to conduct OBD2 diagnostics on any Ford, Lincoln, Mazda, or Mercury vehicle. 

Download: https://forscan.org/home.html

8. OBDwiz – OBD2/elm327 software

Key Features and Functions

OBDwiz performs dealer-level diagnostics. This includes reading and clearing trouble codes, as well as real-time monitoring of onboard sensors. With more than 90 PIDs supported, its data reading capabilities are reasonably comprehensive. This data can be viewed in its customizable dashboard, graphed, and logged for future reference. 

Along with this, OBDwiz supports emission readiness testing, so you’ll know if your vehicle will pass state emissions tests. Its most unique feature is its fuel economy calculator. This records trip data so you can see your average fuel consumption and make adjustments to save at the gas pump. 

The simplicity of OBDwiz is the best feature, though. Its intuitive interface lets anyone diagnose vehicle issues, no matter your level of repair knowledge or experience. 

Vehicle Coverage

OBDwiz supports all 5 of the standard OBD2 protocols, giving it complete compatibility for US vehicles made in 1996 or later. 

Pricing & Updates

OBDwiz is one of the few diagnostic software programs whose full version is available for free. It comes included with a range of OBDLink adapters. The flip side of this is it will only work with those adapters. There is another version of the software, TouchScan, that has the same functions but will work with many adapters. Like the software itself, updates are free for life. 

Operating System Requirements

You can use OBDwiz on any Windows device. Unfortunately, it isn’t compatible with either iOS or Android operating systems. 

Verdict: OBDwiz is both user-friendly and budget-friendly, with extensive data reading and diagnostic functions for any OBD2-compliant vehicle. 

Download: https://www.obdsoftware.net/software/obdwiz

9. ScanMaster ELM – elm327 software

Key Features and Functions

ScanMaster ELM can diagnose all OBD2 systems and monitors. It automatically detects all compatible control devices, with features like reading and clearing trouble codes, view live data, and more. 

ScanMaster can also go beyond OBD2 for many vehicles to read codes and data streams from the transmission, brakes, and powertrain. It’s a great way to monitor your fuel efficiency, too, since it can show you fuel consumption from your trips and let you view live data related to the fuel system. 

The interface of ScanMaster ELM is straightforward and easy to navigate. We also appreciate the helpful Diagnostic Report function, which brings all the readings from your vehicle together in one shareable file. 

Vehicle Coverage

You can read both data and trouble codes from any vehicle compliant with OBD2 or EOBD protocols. This covers US vehicles made in 1996 and later, as well as European vehicles made after 2004. 

This is one of the few diagnostic software programs that will work with older vehicles, too. You can read and erase trouble codes from select OBD1 vehicles, including those made by Opel and Alfa Romeo. 

Pricing & Updates

ScanMaster ELM’s cost ranges from $39 to $59, depending on which version of the software you get. Updates aren’t released as often as for other software programs. That’s nice from a convenience standpoint since you won’t need to worry about downloading new files once you have the software installed. 

Operating System Requirements

ScanMaster ELM is designed for Windows operating systems. It supports both 32 and 64 bit systems, including Windows Vista, XP, 2000, 2003, 7, 8, and 8.1.

Verdict: With broad vehicle compatibility and full OBD2 diagnostics, ScanMaster ELM is an excellent choice for home mechanics and repair professionals. 

Download: https://www.wgsoft.de/scanmaster-elm

10. PCMScan – OBD2 car computer software

Key Features and Functions

Another unique software program from Palmer Performance is PCMScan, a generic OBD2 diagnostic tool designed to work with a broad range of vehicles and hardware. While its functions are relatively basic, it’s an excellent way for everyday drivers and home mechanics to get a glimpse into their engine’s health. 

You can view both trouble codes and data streams with PCMScan. This includes viewing the freeze frame data from the point a trouble code was set. For live data streams, it supports over 220 parameters, including oxygen sensor readings. 

Your control over this data is broader with PCMScan, too. It has the option of assigning a priority to specific PIDs, speeding up the rate of capture for a faster, more accurate diagnosis. We also appreciate the customizable dashboard, which allows you to place the graphs, tables, and maps you need right on your front page. 

Vehicle Coverage

PCMScan supports all vehicles that are compliant with OBD2. This includes the majority of vehicles made in the US, Europe, and Asia after 1996. 

Pricing & Updates

You can download a demo version of the software to try out for free. To get the full functionality, you’ll need to purchase a license code. Once you have that license, you’ll get free access to all upgrades and updates released for the program.  

Operating System Requirements

Similar to other Palmer Performance products, PCMScan is designed to work with Windows. It works with a broader range of operating system versions, however, including Windows 95, 98, SE, ME, 2000, Vista, and XP. 

Verdict: PCMScan is an easy way to conduct basic OBD2 diagnostics on a wide range of supported vehicles. 

Download: https://www.palmerperformance.com/products/pcmscan/index.php

Final Thoughts

Choosing your ideal diagnostic software is a matter of deciding what you need and want from it. For many home mechanics, tuning and coding capabilities are beyond the scope of their knowledge. On the other hand, these can be very useful to repair professionals, allowing you to do more for your customers. 

Whichever one you choose, a diagnostic software program is an easy way to maintain and repair your engine. Use the review above to find the program that’s an excellent fit for you. 


1.What is OBD2?

OBD stands for “On-Board Diagnostics”. This standardized protocol is mostly focused on tracking engine issues that could lead to increased emissions.

2.Are all vehicle systems included in OBD2?

No. The OBD2 protocol is focused on the critical engine systems, including the EVAP system and fuel system. However, issues with the transmission, airbags, or electronic systems may not come up through OBD2. Since these diagnostics aren’t standardized, you may need a manufacturer-specific program, such as FORScan, to monitor and troubleshoot these systems. 

3.What is ECU tuning?

This is a process of modifying the parameters of specific systems in the engine computer. This is often done to increase performance or horsepower, though you can also tune your engine for better fuel efficiency and make other improvements. 

4.How do I use diagnostic software?

Once you’ve downloaded and installed the software, you’ll need to connect your computer to your vehicle using an OBD2 adapter. These adapters plug into the 16-pin connector inside your vehicle, which you’ll usually find under or around the steering column. The specific process of running a diagnosis differs from one program to the next, so you should read the included instructions to learn how to use the program you choose. 

5.How can I tell if the software is compatible with my vehicle?

Some of these programs, such as FORScan, will only work with vehicles made by specific manufacturers. Most of them, however, is compatible with any OBD2-compliant vehicle. If your car has a 16-pin OBD2 port, you’ll be able to conduct diagnostics with one of these programs. 

6.How do I turn off the check engine light using diagnostic software?

Start by reading the diagnostic trouble codes (DTCs) from your engine. This will tell you the specific issues that caused the light to turn on in the first place. Once those problems have been repaired, use the software to clear the codes and turn off the dash warning light.