Markdown Companion

A clean reader for the Markdown your AI tools write — folder sidebar, outline, auto-reload with diff. 100% local, no tracking.

Your projects are full of Markdown that was never written for humans to read raw: READMEs, plans, specs, agent notes — documents your coding assistant produces and updates all day. Chrome opens them as a wall of plain text. Markdown Companion turns them into a clean, GitHub-style reading view, and shows you exactly what changed each time a file is edited. WHAT IT DOES ▸ Renders .md, .markdown, .mdown, .mkd and .mdx files opened from disk (file://) ▸ Complete Markdown Guide coverage, on by default: tables, task lists, strikethrough, footnotes, definition lists, heading IDs, highlight, sub/superscript, emoji shortcodes, fenced code with syntax highlighting — verified by an automated conformance suite on every build ▸ Mermaid diagrams and KaTeX math, rendered inline ▸ What you typed is what you see: no typographic rewriting — a --flag in a runbook stays a --flag; embedded HTML is rendered only after sanitisation ▸ Folder sidebar: every markdown file in the current folder one click away, plus a parent-folder link ▸ Document outline with click-to-scroll and scroll-spy ▸ Raw/rendered toggle: one click shows the exact markdown source, byte for byte ▸ Click any image or diagram to zoom it full screen — wheel, pinch or keyboard to zoom, drag to pan; diagrams stay sharp at any size, and one click saves either as a picture ▸ A word count and reading time above every document ▸ Auto-reload when the file changes on disk — with a diff view that shows precisely what your editor, or your AI assistant, just changed before you accept it ▸ Light, dark and sepia themes, high-contrast mode, adjustable font, width and line height, a print stylesheet, and keyboard shortcuts for the frequent actions BUILT AS A BRIDGE TO YOUR AI TOOLS Markdown has become the shared language between people and AI: agents read your docs for context and write their plans, reports and memory files back as .md. Markdown Companion is the human side of that bridge — the fastest way to actually read what your tools produce, move through a whole folder of generated docs, and review every change they make. No AI runs inside this extension; it is the reading and review surface for the AI already in your workflow. PRIVATE BY DESIGN Everything runs inside your browser. No server, no account, no analytics, no telemetry — file contents never leave your machine. Full privacy policy: https://markdowncompanion.app/privacy/ GETTING STARTED To read local files, Chrome requires you to enable "Allow access to file URLs" for this extension — a one-time step Markdown Companion walks you through on first install.