Markdown Viewer Ultra

Render text/markdown responses and .md files as GitHub-styled Markdown. Light/dark theme. Toggle raw view anytime.

Markdown Viewer Ultra turns any page Chrome would otherwise show as raw text into a clean, GitHub-style document — automatically. If a server responds with Content-Type: text/markdown (or you open a .md / .markdown file served as plain text), the extension parses it with GFM-compatible Markdown, sanitizes the output, and replaces the raw view with formatted HTML: headings, tables, code blocks, task lists, blockquotes, images, and links — exactly as you'd expect them to look on GitHub. WHAT IT RENDERS • text/markdown and text/x-markdown responses • Local and remote .md, .markdown, .mdown, .mkd, .mkdn files served as text/plain • GitHub-Flavored Markdown: tables, task lists, strikethrough, fenced code, autolinks FEATURES • Toolbar popup with three themes: Auto (follows your OS), Light, Dark • Content-width picker: Narrow (920px), Wide (1440px), or Full (fills the window) • Syntax highlighting for ~30 common languages (JavaScript, TypeScript, Python, Go, Rust, Ruby, C/C++/C#, Java, SQL, Bash, JSON, YAML, HTML, CSS, and more) — colors follow the active theme • Mermaid diagrams — mermaid code blocks render as charts, matching the active theme and loaded only when a page contains one • Localized UI in 17 languages: English, Português (BR), Português (PT), Español, Français, Deutsch, Italiano, 日本語, 简体中文, 繁體中文, Русский, हिन्दी, বাংলা, ਪੰਜਾਬੀ, Türkçe, עברית, العربية • "See original" link in the page footer to flip to the raw Markdown source, and "See rendered" to flip back • Same toggles are available in the popup • GitHub-style typography and code-block coloring (including light/dark prettylights palette) • Mobile-friendly responsive layout • Theme + width preferences sync across your signed-in Chrome browsers PRIVACY • No data collection — at all • No network requests — every render happens locally in your browser • No analytics, no telemetry, no tracking • The only things stored are your theme and width preferences, kept in Chrome's built-in storage • On uninstall, Chrome opens the project's feedback page so you can tell us what to fix SECURITY • Output is sanitized with DOMPurify before being inserted into the page • Manifest V3, no remote code, no eval — all libraries (marked, DOMPurify, highlight.js, Mermaid, github-markdown-css) are bundled locally • Open source — review the code yourself HOW TO USE 1. Install the extension 2. (Optional) Enable "Allow access to file URLs" on the extension's details page if you want it to work on local .md files 3. Open any Markdown page — it renders automatically 4. Click the toolbar icon to switch theme, change width, or view the original source PERMISSIONS • Storage — saves your theme and width preferences • Access to all sites — needed because Markdown can be served from any domain, and Chrome only exposes the response MIME type after the page loads. The extension exits immediately on every page that isn't Markdown. Questions, bugs, or feature requests? Open an issue on the project page.