Highlighter.pro

Highlighter.pro is a Chrome extension for highlighting text on webpages and (optionally) adding notes to highlights. It works like a marker for web pages.

It's very fast, very lightweight and does not overload your browser with heavy scripts.

It's open sourced. You can see its code on GitHub and GitLab.

And you can install it from the code repo as well as from Chrome web store

It does not transfer your highlights and notes to remote server and does not require permission to send/receive data to Internet.

You can see how to use it on the video: