DOM Square is a free Chrome add-on developed by Nitesh Vaidya that extends the functionality of the Developer Tools. With DOM Square, developers can enhance their coding experience by accessing a sidebar that offers various useful features.

One of the main features of DOM Square is the ability to use emmet abbreviations. This feature allows developers to quickly generate HTML and CSS code using simple abbreviations. Additionally, DOM Square provides a previewer that allows developers to see the code generated by emmet abbreviations before injecting it into the selected DOM element.

In addition to emmet abbreviations, DOM Square offers several other useful operations. It includes a formatter to ensure consistent and clean code, linters to detect potential errors and improve code quality, and drag and drop functionality for easy manipulation of DOM elements. Developers can also perform WCAG validations to ensure their code meets accessibility standards.

DOM Square provides a range of viewers for different file types, including HTML, CSS, JS, SVG, XML, and API JSON. These viewers allow developers to easily inspect and analyze the contents of these files within the Developer Tools.

One of the standout features of DOM Square is its ability to inject code directly into the selected DOM element. This allows developers to quickly test and experiment with code changes without the need to manually edit the source code.

Overall, DOM Square is a powerful add-on for Chrome's Developer Tools that enhances the coding experience with its emmet abbreviations, code injection capabilities, and various other useful features. Whether you're a beginner or an experienced developer, DOM Square can help streamline your workflow and improve productivity.