The Code Editor is a subscription-based extension for Firefox designed specifically for web development. It offers essential features such as syntax colorization, IntelliSense for code completion, and validation capabilities. Supporting a wide range of languages including HTML, CSS, JavaScript, TypeScript, JSON, XML, YAML, and Markdown, it provides developers with a versatile tool for coding tasks. The interface allows users to edit text areas and view the page source or selected text directly within the editor, enhancing productivity.

One of the standout features of the Code Editor is the Diff Editor, which enables side-by-side live comparison of code, making it easier to spot differences and make necessary adjustments. Additionally, it supports common text encodings and is compatible with other WebExtensions, broadening its functionality. However, potential users should note that the extension may not work well with certain Android input method auto-suggestions.