ChangeDetection.io

ChangeDetection.io is a self-hosted web app that watches web pages for changes and alerts you when content updates. It is commonly used to track price changes, availability, announcements, and updates on pages that do not provide RSS feeds.

Key Features

• Monitor URLs on a schedule and trigger notifications when changes are detected
• Visual change detection (screenshot-based) and text/HTML change detection modes
• Diffs and history: view what changed over time with change snapshots
• CSS/XPath/JSONPath targeting and “ignore/filters” to reduce noise (e.g., remove dynamic elements)
• Supports pages requiring JavaScript rendering via a browser automation backend (Playwright)
• Notification integrations including email, webhooks, and common chat/incident endpoints (via Apprise)
• Optional proxy support for fetching pages
• Import/export and organization tools for managing many watches

Use Cases

• Track price/stock changes on ecommerce product pages
• Watch government/company announcement pages for updates
• Monitor internal or external web pages for regressions or unexpected content changes

Limitations and Considerations

• JavaScript-rendered monitoring requires running a browser automation component (higher CPU/RAM than simple fetches)
• Highly dynamic pages may require careful filtering/targeting to avoid frequent false positives

ChangeDetection.io provides a focused interface for building reliable “watches” on web content, combining diff/history views with robust filtering and broad notification support. It is a practical replacement for hosted change-monitoring services when you want control over scheduling, data retention, and integrations.