CSS Editor & Share Tool

A webapp that lets users add custom CSS to any website in real-time and share the styled result with others. Perfect for designers wanting to quickly test styles or show design ideas without modifying the original site.

Browser-based CSS injection tools have existed for over a decade — Stylish, Stylus, and UserCSS all cover the personal styling use case well, and browser devtools already handle rapid prototyping natively. The "share a styled result" angle is the only genuinely differentiated wedge here, but that workflow collides with purpose-built design collaboration tools like ScreenStudio or even Loom for quick visual communication. Revenue is unclear because the core user — a designer casually testing styles — has low willingness to pay and no obvious team-based upsell unless you build toward a handoff or annotation layer. The most likely failure mode is that the sharing link solves a problem designers tolerate rather than one they actively pay to fix.