The Windows Vehicle Recognition SDK package can be downloaded here:

Before getting started, ensure you have the latest versions of Visual Studio and .NET installed.


Before running the software you must obtain a license key. If you haven't already done so, please visit the Request a License section to submit your information.

After acquiring a license, paste the license key into the license.conf file to begin using the software. Alternatively, you can set the license as an environment variable named OPENALPR_LICENSE_KEY.

Command Line Application

alpr.exe is a command line application that can analyze license plates. Type alpr --help from the Windows command prompt for more information.


# Recognize a US-style plate
alpr -c us samples/us-1.jpg

# Recognize a US-style plate and measure the processing time
alpr -c us --clock samples/us-1.jpg

# Recognize a European-style plate with JSON output
alpr -c eu -j samples/eu-1.jpg


The Vehicle Recognition SDK is written in C++ and has native support for integrating with C/C++ applications.

Vehicle Recognition SDK also includes bindings for C#, Java, and Python. Each of these bindings fully implements the Rekor Scout® API.

All of the DLLs in the root directory are required at runtime in order for the application to function. If you run in C#, Java, or Python, for example, the native DLLs must be accessible to the program so that it can load.

To include Vehicle Recognition SDK in your C/C++ application, include the alpr_c.h file in the include directory. You must also link the libopenalpr.dll shared library to your code.

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