CruxCards

Stop drowning in browser tabs. Start building a knowledge library that thinks. Every day, you discover valuable information while browsing—insightful articles, expert opinions, data that could change your thinking. Yet most of it vanishes into forgotten tabs, lost bookmarks, or the void of "I'll remember this later." Crux Cards transforms how you capture and recall knowledge. What It Does Crux Cards automatically extracts the essence of any webpage and turns it into structured, atomic knowledge cards. Each card captures a single insight in one of six semantic types: Concepts: Definitions and mental models Facts: Specific data points and events Quotes: Memorable statements worth preserving Arguments: Claims backed by evidence Frameworks: Processes and methodologies Theses: Investment ideas with catalysts and risks (perfect for analysts) Unlike traditional bookmarks that just remember URLs, Crux Cards understands what matters on each page and builds connections automatically. Why Users Love It Effortless Capture Click the extension icon on any webpage to generate knowledge cards AI automatically identifies and structures key insights Works on articles, PDFs, YouTube videos, and more Select specific text to create focused cards 100 free credits to get started Intelligent Organization Auto entity extraction identifies people, companies, and key concepts Build an effortless knowledge graph without manual tagging Entity Timeline tracks how your understanding evolves over time See all cards related to any person, company, or topic in chronological order Organize cards into custom folders Smart Recall Related cards automatically surface when browsing similar topics Ask AI to query your personal knowledge base in natural language AI-powered similarity search finds connections you'd miss Your library grows more valuable with every card saved No more "I know I saved this somewhere..." Built for Retention Spaced repetition system with daily review queue Smart scheduling ensures long-term retention Active recall strengthens memory better than passive re-reading Track your learning progress over time Thesis Tracking (Investors) Purpose-built cards for tracking investment ideas Document entry points, catalysts, and risks Track P&L performance alongside your thesis Entity Timeline shows how your view of companies evolves Privacy-First Your cards are stored securely in your personal database Only you can access your knowledge library No data mining or selling your insights Google Sign-In for seamless authentication Perfect For Research Analysts building searchable knowledge bases Portfolio Managers tracking theses and entity timelines Students using spaced repetition for long-term retention Knowledge Workers curating insights for projects Lifelong Learners building their personal knowledge graph Writers collecting quotes and research for articles Investors documenting investment theses and tracking performance How It Works: Capture → Organize → Recall Browse the web as you normally would Click the extension when you find something valuable Review AI-generated cards capturing key insights Save to folders and let AI extract entities automatically Rediscover knowledge through related cards and Ask AI Reinforce learning with daily spaced repetition reviews Key Features ✓ AI-Powered Extraction - Powerful LLM identifies and structures insights automatically ✓ 6 Semantic Card Types - Concepts, Facts, Quotes, Arguments, Frameworks, Theses ✓ Auto Entity Extraction - Build a knowledge graph without manual work ✓ Entity Timeline - Track how your understanding evolves over time ✓ Ask AI (RAG) - Query your knowledge base in natural language ✓ Smart Related Cards - Surface relevant saved knowledge while browsing ✓ Spaced Repetition - Daily review queue for long-term retention ✓ Thesis Tracking - Purpose-built for investment research ✓ Multiple Content Types - Works with articles, PDFs, videos, and text selections ✓ Personal Knowledge Base - Build your second brain in the cloud ✓ Beautiful Design - Premium typography and thoughtful UX ✓ Cross-Device Sync - Access your cards from anywhere ✓ Search & Filter - Find exactly what you need instantly Beyond Bookmarks Traditional bookmarks are like writing down a library's address instead of the book title. They remember where you found information, not what the information was. Crux Cards captures the actual knowledge, structures it semantically, extracts entities automatically, and surfaces it when you need it most. It's not a filing system—it's a thinking partner.