WhatFont is a Firefox extension designed for web developers and designers to quickly identify fonts used on any webpage. By simply clicking the toolbar button, users can hover over text to reveal detailed font information, making it an efficient tool for font recognition without the need for complex inspection tools like Firebug or Webkit Inspector. This user-friendly approach streamlines the process, allowing for instant insights into typography used across the web.

In addition to basic font identification, WhatFont enhances its functionality by detecting the services used for serving the fonts, including popular options like Typekit and Google Font API. This feature is particularly beneficial for developers who wish to maintain consistency in their web projects or seek inspiration from existing designs. Overall, WhatFont stands out as a practical tool for anyone involved in web development and design.