Stemmy - Vocabulary Wallet

The Cognitive Overlay for the Web - Highlight any word for instant AI-powered definitions

Stemmy is a free AI vocabulary builder that turns any webpage into a classroom. Highlight any word for an instant definition with etymology, pronunciation, and examples — then save it to your personal wallet and master it with spaced repetition. 🔮 Ghost Card — Floating overlay with definition, pronunciation, synonyms, antonyms, and etymology. Works on every website. (Ctrl+E) 🧬 Word DNA — Root morpheme, origin language, and related words from the same word family. 💎 Vocabulary Wallet — One-click save. Searchable, sortable, organized by mastery level. 🧠 Spaced Repetition — SM-2 algorithm schedules reviews at optimal intervals for long-term retention. 📍 Encounter Tracking — Detects your saved words on any webpage you browse for passive reinforcement. 📖 AI Stories — Generates short stories using your saved vocabulary for context-rich learning. 🔬 X-Ray Mode — Scans any page and highlights complex vocabulary. Hover to review instantly. 📊 Dashboard — Streaks, activity timeline, detailed word cards, data export/import. 🔑 Free — 10 AI lookups included. Add your own Mistral API key for unlimited usage. 🔒 Private — All data stored locally in your browser. Nothing collected or shared. 🎯 Built for GRE, SAT, TOEFL, IELTS prep · ESL/EFL learners · researchers · writers · avid readers Install Stemmy — free, private, works on every website.