Silent Highlight — Web & PDF Highlighter by Profang

Tired of highlighting extensions that force you to create an account, track your reading habits, or lock basic features behind a paywall? Meet Silent Highlight.

Silent Highlight is a next-generation web and PDF highlighter built on a different philosophy: Zero Friction and Absolute Privacy (Local-First). Simply install it, select text on any webpage or PDF, and start highlighting at the speed of thought. No sign-ups, no cloud, no lag.

🚀 Why is Silent Highlight different? Unlike other highlighters, Silent Highlight isn't a heavy cloud-based application. It's a high-performance tool engineered for professionals and students who value their digital autonomy.

100% Private: Your highlights never leave your computer. Everything is stored safely in your browser's local storage.
Zero Sign-ups: We will never ask for your email. No subscriptions required to get started. It works instantly right out of the box.
Ultra-Lightweight: Engineered for speed. We don't slow down your browsing experience.
Premium Design: Features a modern glassmorphism aesthetic. Your command center lives cleanly in the browser's native side panel (open with Alt+Shift+H), keeping your reading space clutter-free.
🛡️ Built for Data Sovereignty and Research Continuity (v3.0.0)
In this latest major update, we’ve introduced professional-grade protections to safeguard your research:

🛡️ Automatic Safety Net: Silent Highlight triggers an automatic backup before any uninstallation or bulk data import. Even if you remove the extension by accident, your data is safe.
🔐 Data Integrity Protection: Built-in HMAC-SHA256 verification ensures your local database stays healthy and protected against accidental corruption or external tampering. Your knowledge is yours alone.
🔄 Legacy Transition (TextMark Migration): If you are updating from our legacy version (TextMark), all your old highlights and folders are migrated and cryptographically signed instantly in the background for free.
🚀 UX Resilience (Context Guardian): Silent Highlight reconnects automatically after an update. Keep working without interruptions or the need to reload your tabs.
✨ Core Features:
Select & Highlight: A beautiful, contextual floating toolbar appears exactly when you need it, featuring high-contrast icons for perfect visibility.
Full PDF Support: Highlight text directly on web and local PDF documents using the integrated viewer.
Color Coding: Organize your research using 5 vibrant highlight colors.
Smart Side Panel: Open your command center (Alt+Shift+H / Option+Shift+H) to view, search, and filter all your highlights globally.
Story Mode (Logical Thread): Transform your collection into a narrative. Manually reorder highlights to build research outlines regardless of the source page.
Tags & Notes: Add deep context to your highlights with custom tags and detailed Markdown-compatible notes.
Universal Export: Download your data in JSON for backups or Markdown for your favorite tools like Obsidian or Notion.
🛡️ Our Privacy Promise:
Silent Highlight is a pure tool for professionals, researchers, and students who demand the highest standards in privacy and technical reliability. No accounts, no cloud, no friction.

Perfect for researchers, students, developers, and anyone who wants to organize the web privately and without distractions.

Note on Pricing: The basic web/PDF highlighter and local organization tools are 100% free forever. Advanced features (such as cloud synchronization and nested categories) require an optional premium upgrade.

Note on Pricing: The extension is free for basic highlighting and local use. It offers optional paid upgrades for advanced features and synchronization options.