Fonternate is a free Chrome extension designed for web designers and typographers, enabling them to override fonts on any webpage using locally installed fonts. This tool offers users the ability to test typography in real-time, making it easy to compare styles and adjust type settings without modifying the website's code. Key features include font family and weight selection, advanced OpenType controls, and a live preview function that showcases changes instantly on any webpage.

The extension provides a user-friendly experience with persistent settings that save locally, ensuring privacy and no data tracking. Built with modern web technologies like TypeScript and React, Fonternate maintains the original site styles while allowing for non-destructive font overrides. Ideal for professionals looking to experiment with typography in practical scenarios, Fonternate streamlines the testing process with straightforward controls and a focus on user privacy.