Native annotations, no extension.

Annotation tools today are extensions. Each extension is a third party with its own account, its own server, its own privacy posture. Your highlights live in someone else's database. Marginalia builds annotations into the browser itself: same data layer as your tabs and Spaces, same local-first guarantee, same disappearance promise (when you delete a Space, its annotations go with it).

Select any passage on any page. A small color picker appears with five colors and a note option. Pick a color, optionally type a note, hit Enter. The annotation is attached to the URL, the selected text, and the surrounding context. It re-renders the next time you visit the page, even if the page has shifted slightly. Annotations are queryable as data: list all yellow highlights in a Space, search for a phrase in your own notes.

Use Marginalia for: research where you want to mark key passages, learning where you take notes as you read, fact-checking where you want to highlight a specific claim, or simply keeping a personal canon of passages worth returning to. The five colors let you build your own coding system (yellow = key claim, blue = quote to use, etc.).