In the era of LLMs (ChatGPT, Claude, DeepSeek) where Markdown is the universal lingua franca for documentation and agent workflows, reading and validating .md files shouldn’t feel like a chore.
Yesterday, while reviewing a complex technical spec generated by Claude, I opened one of the top Google-ranked online markdown viewers. The result? A massive sticky bottom ad covered nearly 40% of my vertical workspace, and the tool insisted on refreshing the whole page.
That frustrating moment inspired me to spend the weekend building MDPreview — a zero-latency, 100% client-side, distraction-free Markdown viewer & live editor.
💡 Core Engineering Decisions
Here is what went into the architecture:
- 🔒 100% Client-Side Privacy: All Markdown parsing and highlighting happen strictly in your browser’s local memory. No text, tokens, or documents are ever uploaded to any backend server.
- ⚡ Zero-Lag Synchronized Scrolling: Built with Vite and marked.js for sub-millisecond typing response and proportional two-way split scrolling.
- 🎨 Full GitHub Flavored Markdown (GFM): Native support for responsive tables, interactive task checklists, strikethroughs, footnotes, and math expressions.
- 💻 Syntax Highlighting for 180+ Languages: Powered by Highlight.js with automatic language badges and one-click code copy buttons.
- 🌓 Thoughtful Typography Themes: Switch easily between GitHub Light, GitHub Dark, Eye-Care Warm Sepia, and Midnight Dark.
- 📤 One-Click Export: Export cleanly styled standalone HTML files or download
.mdfiles with a single click.
🛠 Tech Stack & Open Source
- Framework: Vite + Vanilla TypeScript + Modern CSS
- Markdown & Highlight: Marked.js + Highlight.js
- Hosting: Cloudflare Pages (Edge CDN)
The full source code is public and open-source on GitHub:
👉 tangtang-it/mdpreview
💬 Looking for Your Feedback!
This is an early release and I’d love to hear from fellow developers:
- What is the most annoying limitation in your current Markdown reading workflow?
- Would client-side PDF-to-Markdown or Markdown-to-Social-Card generation be more useful for the next sprint?
Check it out at https://mdpreview.dev and feel free to share your thoughts below!