VisualPing.io is a new web app that lets you monitor web pages and it sends an email alert when it detect any change in the content of the page. Unlike other web-based change detection tools, Visual Ping is easier to setup and completely free.
It takes 3 easy steps to monitor a web page as illustrated in this screenshot.
Enter the web address (URL) of a web page and Visual Ping will create a screenshot image of that page. You can create a selection anywhere on that page using your mouse and enter your email address. The service will monitor that particular area of the page every hour and whenever it detects a change, it will send you before and after screenshots of the specified area.
I have been testing the service for the last two days against several popular websites – including CNN and nytimes.com that are updated very frequently – and VisualPing.io does seem like a useful service. The email alerts arrive on time and the included before-n-after screenshots images are sharp and clear.
Changes Detected by Visual Ping
Google Docs does require some knowledge of XPath while in the case of Page Monitor, you can visually selected DOM Nodes on a page to add them to your monitor queue. The add-on will also highlight changes in pages that have been modified.