Claude Browser Inspector

A Chrome extension that lets you visually select any element on a webpage and use it as context when working with Claude AI.

How It Works

1. Add target URLs in the extension popup (e.g., localhost:3000, example.com)
2. Hold the activation shortcut (default: Alt) and hover over elements to highlight them
3. Click to select an element
4. Ask Claude what you need — tell it to check window.__selected for the element you picked and use it as context
5. Press Esc to clear the selection

Requires Claude for Chrome extension to communicate with Claude.

Features

• Persistent injection — the inspector survives page reloads automatically
• Custom URL list — choose exactly which sites the inspector is active on
• Configurable shortcut — change the activation modifier (Alt, Ctrl, Shift, Cmd, or any combination)
• Instant toggle — enable/disable the inspector globally with one click
• Zero data collection — all settings stored locally via Chrome sync storage

Installation

From source

1. Clone this repository:

   git clone https://github.com/Jekins/claude-browser-inspector.git
   

2. Open chrome://extensions in Chrome
3. Enable Developer mode (top-right toggle)
4. Click Load unpacked and select the cloned folder
5. Pin the extension for quick access

URL Matching

The extension supports flexible URL patterns:

Input	Matches
google.com	google.com, www.google.com, mail.google.com, ...
localhost:3000	http://localhost:3000, https://localhost:3000
https://example.com	Only https://example.com (strict protocol)
*.example.com	Any subdomain of example.com
example.com/app	Any page under /app path

Architecture

• Manifest V3 with service worker (no persistent background page)
• Injects the element picker into MAIN world via chrome.scripting.executeScript so window.__selected is accessible from the page console
• Uses dynamic injection instead of registerContentScripts to support URL patterns with ports (which Chrome match patterns don't support)
• Modifier config is updated in-place without re-injecting the entire inspector

Privacy

This extension does not collect, transmit, or share any data. All settings are stored locally. See Privacy Policy.

License

MIT