dgtlmoon/changedetection.io

Changedetection.io is a self-hosted tool that automatically monitors web pages for changes and sends you a notification when something on a page is different from the last time it was checked. It solves the tedious problem of manually checking websites for updates, whether that is a product coming back in stock, a price dropping, new content appearing on a page, or any other change you care about. The tool fetches pages on a schedule you configure, compares the current content to the previously saved version, and sends an alert through your chosen notification channel, which can be email, Discord, Slack, Telegram, a webhook, or many others. You can narrow what it watches by targeting specific elements on the page using CSS selectors, XPath expressions, or JSONPath for API responses, so you only get notified when the section you care about changes. For pages that require JavaScript to render or require interactions like logging in or clicking a button before the content appears, changedetection.io can use a Playwright browser engine to load and interact with the page before checking for changes. A visual selector tool lets you click on parts of the page to specify what to monitor. For e-commerce use cases, there is a dedicated price and restock detection mode that extracts product metadata and lets you set upper and lower price thresholds or notify you when an out-of-stock item becomes available. Recent versions also support AI-powered filtering where you write a plain-English rule such as "notify me only when the price drops below 50 dollars" and an LLM evaluates each detected change against that intent. You would use this for tracking product prices, monitoring job listings, watching government or regulatory pages for updates, or any recurring webpage-checking task. The tech stack is Python, deployable via Docker.