MarkLens – Markdown Reader

Lightweight, auditable Markdown reader: outline, folding, resizable sortable tables, Mermaid, and task check-off in local files.

MarkLens turns any Markdown file you open in the browser into a clean, readable page, and makes the tables in it something you can actually work with. TABLES YOU CAN WORK WITH • Drag column edges to resize; double-click to fit the content • Click a header to sort: numbers with thousands separators, sizes (KB, MB), dates and Chinese text sort correctly • Filter rows as you type, view any table fullscreen with a sticky header • Copy a table and paste it straight into Excel or Google Sheets CHECK OFF TASKS IN YOUR FILES • In local .md files, click a task checkbox and [ ] / [x] is saved straight back to the file, no editor needed • Undo from the notification; MarkLens refuses to write if the file was changed elsewhere, and keeps CRLF line endings and BOM • You authorize a folder once; only the line you clicked is changed READ AND NAVIGATE • Sidebar outline with the current section highlighted and heading search • Fold any section; fold or unfold everything at once • Files tab: browse the Markdown files and subfolders next to the document, free • Live reload for local files that keeps your scroll position, folds and table state • Open the file in VS Code at the section you're reading • Text width, font size and line height; light, dark or follow the system MARKDOWN SUPPORT • CommonMark and GitHub Flavored Markdown: tables, task lists, footnotes, GitHub alerts (> [!NOTE]), emoji shortcodes, ==highlight== • Containers from docs sites (::: tip, ::: details, Docusaurus :::note) and definition lists • Syntax highlighting with a copy button for code blocks • KaTeX math and Mermaid diagrams, in local files and on web pages • Box-drawing tables in code blocks stay aligned with Chinese, Japanese and Korean text • Export the current view as HTML to share: one self-contained file with the images embedded, or a file that links to them. Or print it / save it as a PDF with every section expanded • Copy content or location: the Markdown source (with formatting for apps that accept rich text), or the file path and line range to point an AI tool at the right lines. Works on the whole document, one section or selected text • Line numbers in source view; click one to copy that line's location PRIVATE AND AUDITABLE • Collects no data. No account, no analytics, no ads, no server • No access to websites at install: local files only. Turn on .md files on websites yourself if you need them. Optional settings sync goes through your browser account, never to us • No remote code: every library is packaged inside the extension • Open source under the MIT license; the test suite includes 60+ attack samples that must not run any code • Privacy policy: https://github.com/xjin9612/marklens/blob/main/PRIVACY.md GOOD TO KNOW • For local files, turn on "Allow access to file URLs" on the extension's Details page. A welcome page walks you through it after installing. • To read .md files on websites, turn on "Also open .md files on websites" in the popup. The browser then asks for access to all websites, because its permission prompt ignores the part of the address after the site name. MarkLens only runs on addresses that end in .md, .markdown, .mkd or .mdx. Source code, changelog and issues: https://github.com/xjin9612/marklens