Two tools that turn "this looks off" into something a developer can act on: what the element actually is, and how far it sits from the thing beside it.
Naming the component that produced an element is the difference between a bug
report a developer has to go and find, and one they can open straight to.
New
Element inspector. Point at anything and get a stable CSS selector plus an AI-ready Markdown snapshot of the element: its styles, its box, and the React, Vue or Svelte component that rendered it.
Measure. Read an element's dimensions, and the edge-to-edge gap between any two elements, in pixels.
Rearrange the toolbar. Drag the tools into the order you actually use them. The arrangement is remembered.
Improved
No dead share links. The share button hides on localhost, .local hostnames, 127.0.0.1 and non-web addresses, because the person opening your link could never have reached those anyway.
Paste any URL at marklayer.app and annotate the live page in your browser. No install, no account, no sign-up. Recipients of your share links don't need to install anything either.