Online Markdown Editor & Viewer
DocBox is a free Markdown editor and viewer that runs entirely in your browser: open a .md file or folder, switch to Edit mode for a split editor with live preview, jump through the outline, search inside the document, and export it as standalone HTML or PDF — without uploading anything.
How it works
- Open a .md file, drop it onto the window, or paste text in Edit mode
- Edit with a syntax-highlighted editor and live preview side by side (Ctrl+E)
- Diagrams written as PlantUML or Mermaid code blocks render automatically, and $...$ math renders with KaTeX
- Export the whole document as standalone HTML or print it to PDF
Frequently asked questions
- Can I edit Markdown files online without installing an app?
- Yes. Switch to Edit mode for a split view — an editor on the left and a live preview on the right — then export the result or copy the source. No installation and no account.
- Can I view Markdown files without uploading them?
- Yes. DocBox runs entirely in your browser — open the page, drop a .md file in, and it renders immediately. Nothing is installed or uploaded.
- Does it support tables, code blocks and math?
- Yes: GitHub-style tables, task lists, blockquotes, syntax-highlighted code blocks, and KaTeX math written as $...$ inline or $...$ display formulas.
- Can I open a whole folder of documents?
- Yes — open a folder to get a file tree alongside the outline panel, and images referenced with relative paths are resolved from the same folder.
- Is there a dark mode?
- Light and dark themes are both included, and the interface switches between English and Chinese.