How Was This Built? is a Chrome extension designed for anyone curious about the technology behind websites. It offers a one-click analysis that reveals the tech stack, architecture, design systems, and UX patterns used in any site. The tool is adaptable to various skill levels, from beginners to seasoned developers, ensuring that users receive explanations tailored to their understanding. Additionally, it features a follow-up chat option for users to ask further questions regarding the analysis, making it an interactive learning experience.

Key functionalities include the detection of popular frameworks such as React, Vue, and Tailwind, as well as the ability to extract color palettes, fonts, and button styles from analyzed websites. Privacy is a priority, as the extension utilizes local storage with no account setup or tracking required. Users need to complete a one-time setup by entering a free OpenRouter API key to access the instant AI-powered analysis.