Changedetection.io: Free open-source tool for website change monitoring

Have you ever wished for a tool that tracks every tiny change on a website and notifies you instantly? Changedetection.io is that tool. It can monitor new content on news sites, alert you to massive discounts, or notify you when an item is out of stock. Let’s dive into this powerful open-source tool with Tentenai.vn!

What is Changedetection.io?

Changedetection.io is an open-source tool that tracks website changes and sends notifications via Discord, Email, Slack, Telegram, and more. With a simple interface, you just enter the website URL and a label to monitor changes in text, HTML, JSON, and more. Best of all, it’s freely available on GitHub. So, what makes this tool stand out? Let’s explore further with Tentenai.vn!

What can Changedetection.io do?

Automatically track website changes

Simply add a website URL, and Changedetection.io will monitor changes, whether it’s in the HTML code or the content itself—down to individual words, letters, or characters.

Automate browser actions

With the Browser Steps feature, you can set up actions like logging into an account, adding items to a cart, or accepting cookies. This is perfect for tracking websites that require logins or complex interactions. Configure it once, and the tool handles everything before checking for changes!

Instant price and inventory alerts

One of Changedetection.io’s highlights is its ability to track product prices and stock availability. By enabling the “Re-stock & Price detection for single product pages” option, the tool extracts metadata from HTML and offers multiple ways to monitor pricing. You can set alerts for when prices drop below a threshold, spike too high, or when a favorite product is back in stock. All of this is managed through an intuitive dashboard, ensuring you never miss a great deal.

Example: Hunting for a rare bottle of whisky? Changedetection.io will notify you the moment the price drops or stock is replenished, letting you snag it before anyone else!

Highly customizable with powerful filters

Changedetection.io offers a range of filters like “Trigger on text,” “Remove text by selector,” or “Extract text,” and even supports regular expressions. You can target specific elements on a website using xPath, CSS Selectors, or monitor complex JSON data with JSONPath and jq. The tool also lets you switch between a no-JS fetcher (fast) and a Chrome JS-based fetcher for dynamic websites.

Smart scheduling and conditions

Don’t want to check a website 24/7? Changedetection.io lets you schedule monitoring by timezone, days of the week, or even limit it to business hours. You can also set conditional actions.

For example, get notified only when a product’s price falls below $50 or when a website mentions “sale.” Everything is tailored to your needs!

Changedetection.io is suitable for

Ever wished for a personal assistant to keep tabs on web changes? Changedetection.io is the answer! Here’s who can benefit from this tool:

Legal and compliance professionals

Monitor legal documents, government regulations, or industry standards. Get instant alerts for critical updates, ensuring you never miss a thing.

Journalists and Researchers

Detect changes in PDFs, government announcements, or organizational news. You can even create RSS feeds from changes to aggregate information easily.

Security experts and Web admins

Changedetection.io monitors HTML code for unusual changes, supports WebDriver and Playwright for dynamic websites, and ensures PCI compliance or legal document tracking.

Businesses and E-commerce professionals

Online shop owners, retailers, or anyone looking to stay ahead of competitors can track rivals’ prices and inventory. Get alerts when prices change or new stock arrives, and even integrate APIs to automate workflows.

Online shoppers and deal hunters

For deal enthusiasts or those chasing rare items, this tool alerts you to price drops, restocks, or special offers. You can set price thresholds (e.g., under $50) to catch every bargain.

How to Install and Use Changedetection.io

Installation

Docker

Using Docker Compose:

Standalone Docker:

Windows

Ensure Python is installed with the “associate .py files with Python” option.

1. Install setuptools via pip3:

(Required for Python 3.12 and later.)

2. Install Changedetection.io:

3. Start Changedetection.io:

4. Access the UI at:

http://127.0.0.1:5000

You can also use flags like -d (custom data storage path) or -p (different port).

On the change list interface, click Diff to track those changes.

Python Pip

Then visit http://127.0.0.1:5000 to access the UI.

Updating Changedetection.io

Docker

Docker Compose

Filters

Changedetection.io supports XPath(1.0), JSONPath, jq, and CSS. Specify filters based on your needs, using XPath generated from element query tools.

Notifications

The tool supports multiple notification channels (email, Office365, custom APIs, etc.). Set one or more notification URLs in the [edit] tab of a watch.

Examples:

Parse JSON Embedded in HTML

When enabling json: or jq: filters, you can extract and parse JSON embedded in HTML—perfect for JSON-driven e-commerce websites.