A Chrome extension for reading, writing, and organizing local markdown files — fast, private, and fully offline.

• Local file reading via the File System Access API — no uploads, no cloud
• Sidebar file tree with collapsible folders and live filter
• Hot reload — viewer auto-refreshes when you save in an external editor
• Full-text search across all markdown files (⌘K)
• Table of contents with scroll-spy highlighting
• Syntax highlighting for JS, TS, Python, Go, Rust, SQL, CSS, HTML, Bash, JSON
• GitHub Flavored Markdown — tables, task lists, front matter, code blocks
• Recent files history
• Light & dark mode with preference saved

• In-browser editor — edit any file directly, save with ⌘S
• Create new files — add .md files to your folder from the sidebar
• Delete files — remove files with a confirmation prompt
• Find & Replace — ⌘F to search and replace within the editor
• Export to PDF — clean, print-ready output via the browser's print dialog

• Resizable sidebar, adjustable font size, reading width, font family
• 100% offline — no data ever leaves your machine

Install Markdown Browser

1. Clone or download this repository
2. Open icons/generate-icons.html in Chrome → click Download All → place the 4 PNGs in icons/
3. Go to chrome://extensions
4. Enable Developer mode (top-right toggle)
5. Click Load unpacked → select this folder
6. Click the extension icon in your toolbar

1. Click the Markdown Browser icon in the Chrome toolbar
2. In the sidebar, click Open Folder and select a local directory
3. Click any .md file to open it
4. Press ⌘K to search across all files
5. Click Edit in the file breadcrumb to edit the file directly

.md · .mdx · .markdown · .mdown · .mkd · .txt

This extension operates entirely offline. Read and write access to your files is granted only through Chrome's built-in permission dialog at your explicit request. No data is collected or transmitted. See the Privacy Policy for the full policy.

Pure vanilla JS — no build step, no dependencies, no bundler.

markdown-browser/
├── manifest.json        MV3 manifest (v2.0.0)
├── background.js        Service worker (opens app tab)
├── app.html             Main single-page app
├── app.js               App logic
├── app.css              Anthropic-inspired dark/light theme
├── lib/
│   ├── markdown.js      Custom GFM parser
│   └── highlighter.js   Syntax highlighter
├── about.html           About page
├── privacy.html         Privacy policy
└── icons/               Extension icons (PNG)

• In-browser markdown editor with ⌘S save
• Create new files from the sidebar
• Delete files with confirmation
• Find & Replace (⌘F) in editor
• Export to PDF with clean print output
• Persistent search bar in the header
• Visible Edit / PDF buttons in the file breadcrumb

• Initial release: read-only markdown viewer, hot reload, full-text search, TOC, syntax highlighting

Since the dawn of the claude code and codex, I have been working with only markdown files. All of my research, planning, working is in markdowns. I needed something to quickly view my markdown repo, search, edit etc. VS code is good but still have to preview the file, I needed something offline and quick. There are some extensions online but they were paid. So I built one. now its one of the always open tab on my chrome. Hope this helps some markdown guy too. If it does, dont forget to give a shoutout to me on Twitter :P

abhikuchbhi.in

MIT — see LICENSE

abhikuchbhi.in