Tinkerfont.

Tinkerfont: Live Font Testing for Web Designers & Developers

Tinkerfont is a free browser extension that lets you inspect, swap, and test fonts directly on live websites—no DevTools, no deployments, no accounts required. See exactly how 1,900+ typefaces from Bunny Fonts or your own custom uploads perform on real content, layouts, and responsive breakpoints before committing changes to your codebase or design system.

Product Highlights

• Instant Font Swapping: Replace any font on a live page in one click—search Bunny Fonts' open-source library or upload your own .woff2, .woff, .ttf, or .otf files to test brand or client typefaces immediately.
• Live DOM Inspection: Right-click any text to inspect family, color, contrast, and even experimental font file URLs; scan entire pages to see every typeface in use with occurrence counts.
• Scoped Testing: Limit font changes to specific elements or page areas—nav bars, tables, headings only—so you can iterate precisely without disrupting the full layout.
• Persistent Rules: Your swaps and scopes save per hostname in local browser storage, keeping your testing environment intact across refreshes and return visits.
• Zero Data Collection: No account required, no servers involved—Tinkerfont stores everything locally and never transmits your browsing data, with full privacy transparency.

Use Cases

• Design Prototyping: Evaluate typeface candidates on production content before finalizing style guides or Figma mockups, ensuring readability across real device breakpoints.
• Client Presentation: Demo custom or purchased fonts on live client sites without staging environments, giving stakeholders immediate visual proof before development begins.
• Developer QA: Verify font loading, fallback behavior, and performance impact on actual pages rather than isolated test files, catching issues early in the workflow.

Target Audience

Tinkerfont is built for UX/UI designers, front-end developers, and typography enthusiasts who need fast, frictionless font experimentation on real websites without disrupting their existing toolchain or compromising privacy.