Marginal — Highlight, Read & Summarize

Highlight and annotate any page, read distraction-free, and summarize with your own AI key. 100% local storage, no account.

Marginal turns scattered reading into organized, synthesized notes — without leaving the page. **Highlight anywhere.** Select any text on any website to highlight it in one of four colors, add a note, and tag it by topic. Your highlights are saved locally and reappear automatically every time you revisit the page. **Organize in one place.** Open the full-screen Notes view to browse everything you've saved — across every site — as a searchable, filterable grid. Filter by tag, by website, or by color, or just search across all your quotes and notes at once. **Merge and synthesize.** Select multiple highlights and combine them into a single, freely-editable note — perfect for pulling together research from several sources into one coherent write-up. Or let AI do the synthesis for you: summarize any selection of notes with Chrome's built-in on-device AI (free, private, no account needed) or your own Anthropic/OpenAI/Gemini API key. **Read, don't just skim.** A distraction-free reader mode strips away ads and clutter. Built-in text-to-speech reads any highlight or note aloud. **Export anywhere.** Every note — or any summary — exports straight to Markdown, ready to drop into Obsidian, Notion, or wherever you keep your notes. **Your data stays yours.** Highlights and notes are stored locally in your browser. If you use an AI provider that needs an API key, it's stored locally too and used only to call that provider directly — nothing passes through any server we run, because we don't run one.