Tinkerfont

What it does

Tinkerfont is a free Chrome Extension and Firefox Add-on that lets you inspect, replace, and test fonts on live websites without opening DevTools or editing stylesheets. It scans the DOM to list all fonts in use, allows you to swap them with over 1,900 fonts from Bunny Fonts or your own uploaded files, and scopes changes to specific page elements. Rules persist per hostname, and you can share setups with teammates via a link or JSON export.

Who it is for

Tinkerfont is built for designers, developers, and tinkerers who want to experiment with typography on real websites. It's useful for anyone evaluating font choices in context—before committing to a design system change or opening Figma. The tool requires no account and stores data locally, making it accessible for quick prototyping.

Why it matters

Choosing the right typeface is critical for readability and brand identity, but testing fonts on live sites typically involves editing CSS or using design tools that don't reflect real content and breakpoints. Tinkerfont solves this by enabling instant, risk-free experimentation on actual pages. It helps teams make informed typography decisions faster, without disrupting development workflows.

Launch signal

Tinkerfont was launched by solo developer Mighil as a free tool. It is available on the Chrome Web Store and Firefox Add-ons marketplace. The project is supported by optional contributions but remains free to use. The website includes a privacy policy and a "Get started" guide.

Brand and naming

The name "Tinkerfont" combines "tinker" (to experiment or fiddle) with "font," clearly communicating the tool's purpose. The brand is positioned as a playful, developer-friendly utility for typography testing. The tagline "Free font playground for live websites" reinforces its ease of use and zero-cost appeal.