Web annotation tools have emerged as valuable instruments for online learning and knowledge management. However, most existing systems remain limited to text-based highlighting and commenting, lacking intelligent features that actively support comprehension and knowledge retention. This paper presents Highlight Notes, an AI-enhanced browser extension built on the Chrome Manifest V3 architecture that integrates persistent text annotation with color-coded highlights and notes, AI-powered voice note recording using the Web Speech API for transcription and Google Gemini for context-aware transcript refinement, on-demand AI flashcard generation from highlighted paragraphs with diverse question types, AI-powered quiz evaluation that semantically assesses user answers, and comprehensive export functionality supporting PDF and JSON formats with full Arabic and right-to-left text rendering. The system employs a client-server architecture with a PHP/MySQL backend and supports bilingual content in both English and Arabic. The extension incorporates a multi-node text highlighting algorithm that robustly handles text spanning complex DOM structures, along with an annotation statistics dashboard for monitoring user engagement. Experimental evaluation with university students demonstrates that AI-powered voice notes reduce note-taking time compared with typed notes, while the flashcard and quiz functionality significantly improves short-term knowledge retention. The system is designed to prioritize user control, privacy, and educational effectiveness.
