Glasp is a browser-based highlighter for the web, PDFs, YouTube videos, and Kindle books, built for people who read to think rather than to skim. A reader selects a passage on any page, adds a short note while the thought is fresh, and Glasp files it into one searchable library organized by tag and author. Founder Kazuki Nakayashiki launched the product in San Francisco in 2021 with co-founder Kei Watanabe, building on the idea that knowledge people accumulate in private notebooks shouldn't disappear once the tab closes.
What separates Glasp from a standard bookmarking tool is the AI layer sitting on top of a user's own highlights. Every saved passage feeds a personal model that can summarize an article before a reader commits to it, answer questions grounded only in what that person has actually saved, and resurface a half-remembered idea from a plain-language description. An MCP connector carries this personal library into ChatGPT or Claude directly, so the highlights become working context rather than a static archive.
Glasp also leans into the social side of highlighting: saved passages can be shared without requiring the recipient to log in, and a knowledge graph surfaces other readers who highlight similar material, letting users follow people whose taste in ideas overlaps with their own. The core highlighter, unlimited saves, and sharing are free; a Glasp Pro tier extends the AI memory features for heavier users. The mobile app was rebuilt in 2026 with a dedicated reader and a home-screen widget for daily review.
