Knowledge Book

A searchable book for everything you highlight - with a cute page buddy that saves, snaps, reminds and plays. AI & Obsidian ready.

Every day you read sentences worth keeping — and lose them. Knowledge Book is where they go instead: highlight text on any page and it's saved into a beautiful, searchable book of notes, with the source, page and date remembered for you. THE BOOK — FREE, FOREVER • Highlight → save, with one click or Ctrl+Shift+S • A journal that organizes itself: notebooks, tags, sources • Instant search across everything you've ever kept • One-click export to Obsidian (Markdown with frontmatter) • Automatic backup to a folder you choose — your notes are files you own • Optional AI powers with your own API key (OpenRouter, OpenAI, Claude or Gemini): summaries, and ✨Ask — questions answered from your own notes • Your data stays yours: notes live on your device, AI calls go directly from your browser using your key, and nothing is sent anywhere else THE PAGE BUDDY — BUDDY PRO A tiny companion who lives on your pages and does real work: it offers to save what you highlight, snaps page snapshots, delivers reminders in person, levels up as your book grows — and keeps you company. Feed it treats, play noughts & crosses and rock·paper·scissors against it, and share notes with a friend in real time, buddy to buddy. Buddy Pro is a one-time purchase, not a subscription. Try everything free for 3 days. Then from $5.99 once — Pebble the rock included — with five more characters (cat, dog, blob, plant, mage, witchling) from $1.60 each, or the whole family in one payment. Licences work on up to 5 browsers, and refunds behave honestly. The book never locks. Saving, search, tags, notebooks, export and backup are free forever — the buddy is the only thing you ever pay for. Made with care by a person who always wanted a buddy. Questions? The support link is right here on this page.