Vistree visualizes your markdown heading structure as a horizontal mindmap. Drag nodes to reorder sections, move them across heading depths (h2 becomes h3 automatically), and export clean markdown. Built for long markdown files, AI-generated docs, handoff memos, READMEs, where scrolling and manual cut-and-paste breaks your flow. Unlike read-only visualizers like Markmap, Vistree lets you restructure your document and get markdown back. No signup. No install. Runs in the browser.