It’s important to show highlights & notes in context, but the web platform itself is unstable, pages might be changed at anytime. So highlights and notes should be preserved regardless of the page.

Scribble
Limited free account

Diigo
Limited free account, good enough.

Weava

Highly
Free plan only support public highlights. Doesn’t support annotation.

hypothes.is
free. Support highlight and annotation. Support tagging. Decent search. It has tag overview with count, good! But you have to tag each highlight or annotation, kind of sad. But good enough.

Evernote
Hard to take multiple highlight on same page (can do by saving multiple notes and then merge together). Highlights and annotations will probably make Evernote a cluster? Tagging is acceptable. Can not show highlights & notes in context.