Glasp

Glasp is a social web highlighter. With its browser extension you can highlight and annotate text on any web page or PDF, collect everything in one place and, if you like, share your highlights publicly to learn alongside others with similar interests.

Glasp is also well known for its YouTube summaries: it shows a video's transcript and can create an AI summary of it, so you can skim long videos quickly. You can import Kindle highlights, export notes to tools such as Notion and Obsidian, and use AI to summarise and connect your saved ideas. Over time your highlights become a personal, searchable knowledge library.

Good fit if you: read a lot online and want to save, organise and revisit the most useful parts.
Less ideal if you: prefer offline paper notes or don't want any social or sharing features.

Pricing: free; premium plans add more AI features and export options.