There are a lot of reasons you might want to build a browser extension. For some, it might be the extra functionality that is not possible in a sandboxed website, such as launching your company's desktop application from your web app. For others, it might be to add a browser feature that strengthens the integration with your web app, like the ability to save and tag images from pages across the web. For yourself, it might be just wanting to solve a personal grievance with the web.

Browser extensions are still as relevant today as ever, and with the help of cross-browser standards have never been easier to develop. In under an hour, we will cover the core components of a browser extension, the extension API, and create a browser extension that can be side-loaded onto all of the most popular web browsers and be ready to submit to the store.