SiteMark by Niels van Brakel

Ever changed something on production while you thought you were on test? SiteMark makes the difference impossible to miss.

Group the sites that belong together, say "Production", with URL patterns, from simple wildcards like *.example.com to careful regular expressions. SiteMark then marks every matching page with a corner ribbon, a banner, a frame around the window, a tint, stripes or a watermark, in the color you choose.

You can also mark a single element: pick the button that deletes customers and give it an outline or a ribbon. The mark follows the element while you scroll. In the tab bar, an optional title prefix and a tinted favicon keep the difference visible there too, and you can hide the marks on one tab when you need a clean screenshot, with an optional keyboard shortcut.

SiteMark is private by design. It asks for access per website, only when you add it, and runs nowhere else. There are no accounts, no analytics and no servers, and your settings stay in your browser. You can export and import them as a file.

It works with the keyboard, in light and dark, in English and Dutch. SiteMark is open source (MIT).