How to create and test your own simple Chromium-based browser extensions?

Creating your own Chromium-based browser extension is a great way to automate routine tasks or add new functionality to your favorite sites. Modern browsers use the Manifest V3 standard, which defines the structure and operating rules for add-ons. To get started, you do not need complex tools; a standard text editor and the browser itself in developer mode are sufficient.

The development process begins by creating an empty folder on your computer where all the files of your future project will be stored. The main file of any extension is a manifest named manifest.json, which contains metadata: name, version, description, and a list of requested permissions. Script files, stylesheets, and graphical interface elements that will be used in your mini-application are placed in this same directory.

To load and test your created extension in Google Chrome, Yandex Browser, or Microsoft Edge, follow these steps:

After successful loading, your extension's icon will appear on the browser toolbar. Whenever you make changes to the code files, you simply need to return to the extensions page and click the reload button (circular arrow) under your project card. For debugging and finding potential errors, use the built-in developer console, accessible by clicking the Inspect views or Background pages links.