Osmomark — Semantic Highlighter

Visually annotates web pages with semantic symbols for quick comprehension & recall. Local WebGPU NER, 100% client-side.

Osmomark turns any webpage, PDF, DOCX, PPTX, TXT, or Markdown file into a focused study session — automatically. Instead of dumping 28 messy entity colors on the page, Osmomark uses a 5-color semantic model that mirrors how you actually study: 🟡 TERM — key concepts and named ideas 🔵 DEFINITION — explanatory clauses ("X is Y", "X means…") 🟢 EXAMPLE — concrete instances, years, percentages, named cases 🟣 RELATION — comparisons, cause-and-effect, connectors 🔴 WARNING — limitations, caveats, "do not", important notes A hard 15% highlight cap keeps pages readable instead of neon-soaked. KEY FEATURES • Smart highlighting — compromise.js NLP + TF-IDF ranking, runs 100% on-device • Active Recall modes — hide terms, hide definitions, example→term, relation chains, warning drills • SM-2 spaced repetition — automatically queue recalled phrases for review • Document upload — drop a DOCX, PDF, PPTX, TXT, or MD file and study it like a webpage • Symbol packs — switch between Default, Academic, and Business glyph sets, or import your own .glyph.yaml • Shift-click override — relabel any phrase; the extension learns your preferences across pages • Per-site rules — disable on domains you don't want highlighted • Personal notebook — save entities you want to revisit • Density slider — Minimal → Subtle → Standard → Dense → Full • Deep Mode (optional) — enhanced NER with WebGPU/WASM backend • Dark, minimal UI designed to disappear until you need it PRIVACY-FIRST Osmomark does all text analysis locally in your browser. Page content is never sent to any server. See the privacy policy for details. FREE + PRO The free tier includes all 5-color highlighting, active recall, spaced repetition, and document upload. Pro unlocks unlimited Deep Mode scans and priority features. No account needed for the free tier. Made for students, researchers, and lifelong learners who want to read actively, not passively.