Arduino Libraries

Add built-in, third-party, and custom Arduino libraries to your Wokwi projects using the Library Manager and the libraries.txt file.

To include a library, go to the code editor and type # on an empty line. You’ll see an autocomplete dropdown with #include suggestions for popular libraries.

By default, Wokwi compiles your code with the standard built-in Arduino libraries, such as Wire.h and SPI.h.

Adding third party libraries

1. Open Library Manager

   Go to the “Library Manager” tab in the code editor, and press the blue ”+” button.

2. Search for library

   Type some text in the search box to search for a library (e.g. “FastLED”).

3. Add library

   Click on one of the library names in the list to add it.

You can use this method to install any Arduino library from the Arduino Library Manager.

Uploading custom libraries

This feature is only available for paying users.

Paying users can upload any Arduino library by selecting a folder from their computer.

1. Open upload dialog

   Click on the blue ”+” button in the Arduino library manager and then click on “Upload a Library”.

2. Select folder

   Choose the folder containing the library source code (.h and .c/.cpp files).

3. Wait for upload

   Wokwi will zip the contents and upload it to the Wokwi build server. You will see the library in the Library Manager as a .zip file.

Anyone who opens the project will be able to download the library from the Library manager. Any user who creates a copy of the project will be able to use the library in the copied project.

The libraries.txt file

When you add libraries through the built-in “Library Manager”, it will create a “libraries.txt” file in your project. It is a simple text file that lists all of libraries installed in your project, one library per line. Lines that start with ”#” are comments.

Normally, you don’t need to edit this file yourself - the “Library Manager” does this for you. But you can find this file useful if you want to install a specific version of a library. To select a specific version, add ”@” after the library name, followed by the version that you want to install.

For example, the following file will install the latest versions of Servo and FastLED, as well as version 2.3.0 of MySensors:

# Sample libraries.txt file:
Servo
FastLED

# Install a specific version of a library:
MySensors@2.3.0

Custom libraries have the following format: the library name, followed by the text “@wokwi:”, and a unique identifier of the library’s zip file on Wokwi’s servers. You can copy custom libraries to a different project by copying the relevant lines from libraries.txt into the other project.