Chrome Extension - Changedetection.io

The changedetection.io Chrome extension allows you to quickly add the current web page to your changedetection.io instance with a single click, making it easy to start monitoring any page you’re currently viewing.

Features

The Chrome extension provides:

One-Click Add - Add current page to changedetection.io instantly
Automatic Sync - Connects to your self-hosted or cloud instance
Simple Setup - Just install and connect with your API key
Browser Integration - Works seamlessly as you browse
Secure Connection - Uses API authentication to protect your instance

Installation

Step 1: Install from Chrome Web Store

Visit the Chrome Web Store extension page
Click “Add to Chrome”
Confirm by clicking “Add extension”

The extension icon will appear in your Chrome toolbar.

Step 2: Connect to Your Instance

After installation, you need to connect the extension to your changedetection.io instance:

Click the extension icon in your toolbar
Enter your changedetection.io instance details:
- Instance URL - Your changedetection.io URL (e.g., http://localhost:5000 or https://your-instance.com)
- API Key - Your personal API key from changedetection.io
Click “Sync” or “Connect”

Getting Your API Key

To obtain your API key from changedetection.io:

Open your changedetection.io web interface
Go to Settings (gear icon)
Navigate to API section
Copy your API Key
If no key exists, click “Generate API Key”

Keep your API key secure - it provides full access to your changedetection.io instance.

Using the Extension

Adding a Watch

Navigate to any web page you want to monitor
Click the changedetection.io extension icon in your toolbar
The extension will:
- Capture the current page URL
- Send it to your changedetection.io instance
- Create a new watch automatically
You’ll see a confirmation message
The watch appears in your changedetection.io dashboard

What Gets Added

When you add a page via the extension:

URL - The current page URL is captured
Title - Page title is used as watch name (default)
Default Settings - Uses your instance’s default watch settings
Fetcher - Uses your configured default fetcher (HTTP or browser)

Customizing the Watch

After adding via extension, you can customize in the web interface:

Open changedetection.io dashboard
Find the newly added watch
Click Edit to configure:
- Check frequency
- Filters and selectors
- Notifications
- Browser type
- And more

Configuration

Multiple Instances

You can switch between different changedetection.io instances:

Click the extension icon
Click settings or configuration
Enter new instance URL and API key
Click “Sync” to connect

The extension remembers your last connected instance.

Self-Hosted vs Cloud

The extension works with: Self-Hosted Instances

http://localhost:5000
http://192.168.1.100:5000
http://changedetection.local:5000

Cloud Instances

https://your-instance.changedetection.io
https://custom-domain.com

For self-hosted instances on localhost, ensure changedetection.io is running and accessible when you try to add watches.

HTTPS and Security

For secure connections:

Use https:// URLs for cloud instances
Self-signed certificates may require browser trust configuration
The extension validates SSL certificates by default

Troubleshooting

Extension Not Connecting

Check Instance URL

# Verify changedetection.io is accessible
curl http://localhost:5000/api/v1/watch

# Or use browser
open http://localhost:5000

Verify API Key

Check API key is copied correctly (no extra spaces)
Regenerate API key in Settings if needed
Ensure API access is enabled in changedetection.io

Network Issues

If using localhost, ensure changedetection.io is running
Check firewall isn’t blocking the connection
For remote instances, verify URL is accessible from your browser

”Failed to Add Watch” Error

Common causes:

Invalid API Key
- Solution: Regenerate and re-enter API key
Instance Not Accessible
- Solution: Verify instance URL is correct and reachable
API Disabled
- Solution: Check API is enabled in changedetection.io settings
CORS Issues
- Solution: Ensure changedetection.io allows extension origin

Extension Icon Not Appearing

Check extension is installed: chrome://extensions/
Ensure extension is enabled
Pin extension to toolbar:
- Click puzzle piece icon in Chrome
- Click pin icon next to changedetection.io extension

Localhost Connection Fails

For Docker users: If changedetection.io runs in Docker, localhost from browser may not reach container:

# Option 1: Use host IP address
http://192.168.1.100:5000

# Option 2: Use Docker host
http://host.docker.internal:5000  # Mac/Windows
http://172.17.0.1:5000            # Linux

# Option 3: Expose on 0.0.0.0
docker run -p 0.0.0.0:5000:5000 ...

Limitations

The Chrome extension has some limitations:

Browser Compatibility

Chrome/Chromium - Full support
Edge - Should work (Chromium-based)
Brave - Should work (Chromium-based)
Firefox - Not currently supported
Safari - Not currently supported

Feature Limitations

Cannot Configure:

Specific filters or selectors
Check frequency
Notification settings
Browser type (Playwright vs HTTP)
Custom headers or authentication

These must be configured after adding the watch via the web interface. Cannot:

Edit existing watches
Delete watches
View watch status
Trigger immediate checks
View change history

Use the main changedetection.io web interface for these operations.

URL Limitations

Supported:

http:// and https:// URLs
Public websites
Authentication via URL credentials
Dynamic URLs with parameters

Not Supported:

file:// local files
chrome:// internal pages
chrome-extension:// extension pages
Password-protected sites (add via web interface with Browser Steps)

Privacy and Security

What the Extension Accesses

Current Tab URL - Only when you click to add a watch
Current Tab Title - Only when you click to add a watch
Your API Key - Stored locally in extension settings
Instance URL - Stored locally in extension settings

What the Extension Does NOT Do

Does not track your browsing history
Does not read page content
Does not send data to third parties
Does not run on every page automatically
Only activates when you click the icon

Data Transmission

When you add a watch:

Extension reads current URL and title
Sends to YOUR changedetection.io instance via API
Uses YOUR API key for authentication
No data sent to changedetection.io developers or third parties

The extension is open source. You can review the code at the GitHub repository.

Advanced Usage

Keyboard Shortcuts

You can set up keyboard shortcuts for the extension:

Go to chrome://extensions/shortcuts
Find “changedetection.io Website Monitor”
Click in the shortcut field
Press your desired key combination (e.g., Ctrl+Shift+D)
Now press that combination to add current page

Bookmarklet Alternative

If you can’t install extensions, use a bookmarklet:

javascript:(function(){
  var url='http://localhost:5000/api/v1/watch';
  var apiKey='your-api-key-here';
  fetch(url,{
    method:'POST',
    headers:{
      'X-API-KEY':apiKey,
      'Content-Type':'application/json'
    },
    body:JSON.stringify({
      url:window.location.href,
      title:document.title
    })
  }).then(r=>alert(r.ok?'Added!':'Failed'));
})();

Replace http://localhost:5000 and your-api-key-here, then save as a bookmark.

API Integration

The extension uses the changedetection.io REST API. You can replicate its functionality:

curl -X POST 'http://localhost:5000/api/v1/watch' \
  -H 'X-API-KEY: your-api-key' \
  -H 'Content-Type: application/json' \
  -d '{
    "url": "https://example.com",
    "title": "Example Watch"
  }'

See the API Documentation for more details.

Source Code

The extension is open source and available on GitHub:

Repository: github.com/dgtlmoon/changedetection.io-browser-extension
Issues: Report bugs or request features on GitHub
Contributions: Pull requests welcome

Frequently Asked Questions

Can I use this with the paid subscription?

Yes! The extension works with both self-hosted and the official changedetection.io subscription service.

Does this work with other browsers?

Currently only Chrome and Chromium-based browsers (Edge, Brave) are supported. Firefox support may come in the future.

Can I add watches in bulk?

No, the extension adds one watch at a time. For bulk imports, use the Excel import feature in the web interface.

Does it support Browser Steps?

No, the extension creates basic watches. Configure Browser Steps afterward in the web interface.

Can I customize default settings for extension-added watches?

Yes, set your desired defaults in changedetection.io Settings. The extension uses these defaults when creating watches.

Is my API key safe?

Your API key is stored locally in your browser’s extension storage, not transmitted anywhere except to your configured changedetection.io instance.

Can I install it manually?

Yes, download from GitHub and install in developer mode:

Download the extension code from GitHub
Go to chrome://extensions/
Enable “Developer mode”
Click “Load unpacked”
Select the extension folder

API Documentation - Complete API reference for automation
Getting Started - Set up your first watches
Playwright - Configure browser-based monitoring
Importing Watches - Bulk import watches via Excel

Get Started

Installation

Core Features

Content Extraction

Browser Integration

Configuration

Advanced

​Features

​Installation

​Step 1: Install from Chrome Web Store

​Step 2: Connect to Your Instance

​Getting Your API Key

​Using the Extension

​Adding a Watch

​What Gets Added

​Customizing the Watch

​Configuration

​Multiple Instances

​Self-Hosted vs Cloud

​HTTPS and Security

​Troubleshooting

​Extension Not Connecting

​”Failed to Add Watch” Error

​Extension Icon Not Appearing

​Localhost Connection Fails

​Limitations

​Browser Compatibility

​Feature Limitations

​URL Limitations

​Privacy and Security

​What the Extension Accesses

​What the Extension Does NOT Do

​Data Transmission

​Advanced Usage

​Keyboard Shortcuts

​Bookmarklet Alternative

​API Integration

​Source Code

​Frequently Asked Questions

​Can I use this with the paid subscription?

​Does this work with other browsers?

​Can I add watches in bulk?

​Does it support Browser Steps?

​Can I customize default settings for extension-added watches?

​Is my API key safe?

​Can I install it manually?

​Related Documentation

Build docs developers (and LLMs) love

Features

Installation

Step 1: Install from Chrome Web Store

Step 2: Connect to Your Instance

Getting Your API Key

Using the Extension

Adding a Watch

What Gets Added

Customizing the Watch

Configuration

Multiple Instances

Self-Hosted vs Cloud

HTTPS and Security

Troubleshooting

Extension Not Connecting

”Failed to Add Watch” Error

Extension Icon Not Appearing

Localhost Connection Fails

Limitations

Browser Compatibility

Feature Limitations

URL Limitations

Privacy and Security

What the Extension Accesses

What the Extension Does NOT Do

Data Transmission

Advanced Usage

Keyboard Shortcuts

Bookmarklet Alternative

API Integration

Source Code

Frequently Asked Questions

Can I use this with the paid subscription?

Does this work with other browsers?

Can I add watches in bulk?

Does it support Browser Steps?

Can I customize default settings for extension-added watches?

Is my API key safe?

Can I install it manually?

Related Documentation