Markdown Viewer – Local Files, Mermaid & Math

Preview local and online Markdown with a file browser, outline, code highlighting, Mermaid diagrams, math and dark mode.

Read local and online Markdown files directly in Chrome. Markdown Viewer turns plain-text documents into a comfortable reading view with a file browser, a clickable outline, syntax highlighting, diagrams and math. FOR TERMINAL AND AI CODING WORKFLOWS Working with Markdown generated by an AI coding assistant or written in your terminal? Save the document as a local .md file and open it in Chrome to review formatted headings, code, diagrams and math. Keep the terminal for writing and the browser for reading project plans, implementation notes and reports. Reading the saved file can reduce the need to ask an AI assistant to repeat a document just to view it in a more readable format, potentially saving output tokens on those repeat requests. Actual savings depend on your workflow; the extension does not change AI model token usage or connect automatically to a terminal or AI service. READ AND NAVIGATE • Open .md, .mdx, .mkd and .markdown files, including uppercase extensions. • Browse nearby files and folders in one sidebar and document headings in another. • Collapse each sidebar independently; use drawers in narrow windows. • Keep your directory browsing position when opening another document. • Preview supported images, text files, HTML and PDFs from the file browser. CODE, DIAGRAMS AND MATH • Read highlighted code blocks and copy code with one click. • Render Mermaid flowcharts and other supported Mermaid diagrams. • Render Graphviz / DOT diagrams and KaTeX math expressions. • Read tables, task lists, footnotes, GitHub-style alerts and other supported Markdown syntax. A COMFORTABLE READING VIEW • Light, dark and system appearance. • Centered or full-width layout. • Switch between the rendered document and its original Markdown. • Enlarge images with a click. • Optionally refresh changed documents while preserving your reading position. • Print-friendly styling and configurable keyboard shortcuts. GET STARTED Install the extension and open a Markdown document. For local files, open chrome://extensions, find Markdown Viewer, choose Details, and enable “Allow access to file URLs”. Then open or drag a local Markdown file into Chrome. Online URLs must serve the Markdown text itself; a website's HTML preview page is not a raw Markdown file. Online folder browsing requires the server to provide a directory listing. A server that forces file downloads may prevent in-tab preview. MDX files are read as Markdown; JSX components are not executed. PRIVACY Documents are rendered in your browser and are not uploaded to a developer-operated server. No ads, analytics or account registration. Preferences may sync through Chrome according to your browser settings. Online documents and their referenced resources can make normal requests to their hosts. See the privacy policy for details. Interface languages: English, Simplified Chinese, Traditional Chinese, Korean and Ukrainian.