Markdown Writer

Markdown Writer is a free, browser-based markdown editor that shows your writing and its rendered output side by side. Type on the left, and the right pane updates instantly with formatted text, tables, math equations, diagrams, and syntax-highlighted code blocks. It runs entirely in your browser with no signup required, and documents stay on your device unless you choose to publish them. The editor supports GitHub Flavored Markdown plus extensions like footnotes, task lists, and alert callouts, making it a solid choice for everything from quick notes to technical documentation.

What sets Markdown Writer apart is its combination of simplicity and useful extras. The synced scrolling keeps both panes aligned, so you never lose your place. Math and diagrams render inline using KaTeX and Mermaid, which is handy for academic or technical writing. You can export a print-ready PDF with one click. The editor also includes optional AI features: generate a structured markdown document from a short prompt, or select any passage and ask the AI to rewrite it — tighten the text, change the tone, or continue writing. These AI actions work inline, letting you review and accept changes without leaving the editor.

Markdown Writer is ideal for anyone who writes in markdown regularly — developers drafting READMEs, students taking notes with formulas, or bloggers composing posts. Because it works offline after the initial load and saves to local storage, it's also a reliable tool for writing on the go. The AI features are a nice bonus for getting past a blank page or polishing a draft, but the core editor is fast and focused enough to use without them.