Changedetection.io is a website monitoring service that allows users to track changes on web pages and receive notifications when those changes occur. The service is particularly useful for monitoring prices, product restock availability, and other important website updates.

Some of Changedetection.io's key features include:

• Monitoring of specific elements: Users can select specific elements on a webpage to monitor, such as prices or product availability.

• Browser steps: The service can perform actions within a browser, such as logging in, adding items to a cart, and interacting with website forms.

• Restock alerts: Users can receive notifications when out-of-stock products become available again.

• Multiple notification formats: Notifications can be delivered via a wide range of platforms, including Discord, Slack, Telegram, email, and more.

• Flexible monitoring options: Users can set re-check times from 5 minutes and choose virtual locations to access websites from.

• Advanced filters: The service offers features such as trigger text, CSS/xPath rules, and ignore text to refine monitoring criteria.

Changedetection.io offers both a free open-source project and a subscription-based service. The subscription service includes features such as support for up to 5,000 URLs, a dedicated Chrome browser for Javascript websites, and access to various proxies.