MarkdownLab is a fast, fully offline PWA Markdown editor for devs and technical writers tired of broken diagrams, math rendering, and previews. Built with vanilla JS — no backend, no signup, no tracking. Key Features: • 10+ Mermaid diagrams • Full KaTeX Math (with MathML) • Complete GFM incl. alerts • 190+ syntax highlighting • Multi-file workspace • Vector PDF export • 100% offline Perfect for READMEs, design docs, and research notes.

Hey Product Hunt! 👋 I built MarkdownLab because I was frustrated with existing Markdown editors constantly breaking Mermaid diagrams, KaTeX math, or GitHub alerts - especially when working offline or on large docs. So I created a fast, fully offline PWA using only vanilla JS. No backend, no account, no tracking. Everything (including complex diagrams and math) runs smoothly in the browser. It now supports 10+ Mermaid types, perfect KaTeX rendering, full GFM, multi-file projects, and beautiful vector PDF export. Would love your honest feedback - especially on the rendering quality and what features you'd want next. Try it here: https://markdownlab.vercel.app/ GitHub: https://github.com/invincible04/... Thank you!

MarkdownLab

Offline Markdown editor with Mermaid, KaTeX, & PDF export

Offline Markdown editor with Mermaid, KaTeX, & PDF export