Obsidian HTML Preview

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A live HTML preview plugin for Obsidian, inspired by VSCode's Live Preview. It starts a local HTTP server, serves your HTML files with auto-reload on save, and provides an embedded preview panel inside Obsidian — plus the ability to open in your system browser.

Features

• Local HTTP Server — Serves .html files from their parent directory, so relative paths, CSS, JS, fonts, and images all work correctly.
• Auto-Reload on Change — Uses WebSocket to push reload signals to the browser. Edit your HTML (or linked CSS/JS), and the preview refreshes automatically within ~300ms.
• Embedded Preview Panel — A dedicated Obsidian pane (right sidebar or any split) renders your HTML in an iframe pointed at the local server.
• Open in Browser — One command to open the current preview in your system's default browser.
• Path Traversal Protection — The server only serves files within the chosen directory. Requests attempting directory escape are rejected.
• Port Auto-Increment — If the configured port is busy, the server automatically tries the next available port.

Installation

Obsidian Community Plugins

Search "HTML Preview" in Settings → Community plugins → Browse, then install and enable.

Manual

1. Download main.js, manifest.json, and styles.css from the latest release.
2. Place the files into <vault>/.obsidian/plugins/live-preview/.
3. Reload Obsidian (Cmd/Ctrl + R).
4. Go to Settings → Community plugins → Installed plugins and enable HTML Preview.

BRAT

1. Install the BRAT plugin.
2. In BRAT settings, add this repository: HxWGuang/obsidian-live-preview.
3. Enable the plugin in Community plugins.

Usage

1. Open any .html or .htm file in your vault — the preview starts automatically in the right sidebar.
2. Edit the file. The preview refreshes automatically.
3. Use the command palette (Cmd/Ctrl + P):
   • Start HTML Preview — Manually start the preview for the active HTML file.
   • Stop HTML Preview — Shut down the local server.
   • Open Preview in Browser — Open the current preview page in your system browser.

Settings

Setting	Default	Description
Port	5500	Starting port for the local HTTP server. Auto-increments if busy.
Debounce delay	300 ms	Delay after a file change before the preview refreshes.

Security

• The HTTP server binds to 127.0.0.1 (localhost only) — no external network access.
• Only whitelisted static file extensions are served (.html, .css, .js, images, fonts, etc.).
• Path traversal attempts (e.g., ../../../) are blocked at the server level.
• The embedded preview uses an iframe with sandbox attributes for isolation.

Development

# Clone the repository
git clone https://github.com/HxWGuang/obsidian-live-preview.git
cd obsidian-live-preview

# Install dependencies
npm install

# Build
npm run build

# Copy to your vault for testing
cp main.js manifest.json styles.css /path/to/vault/.obsidian/plugins/obsidian-live-preview/

Tech Stack

• Language: TypeScript
• Bundler: esbuild
• WebSocket: ws
• Platform: Obsidian Plugin API, Node.js http module
• Minimum Obsidian Version: 0.15.0
• Desktop Only (uses Node.js built-in modules for the HTTP server)

License

MIT