Most Web sites changes frequently, and it's sometimes useful to know what these changes consist of. SiteDelta is an extension for Firefox that can identify changes made to a Web page since your last visit and even tell you what the previous version of the page said.
Like most Firefox extensions, SiteDelta requires a browser restart to finish installation. Once installed, the extension appeared as a delta symbol (a triangle) in Firefox's status bar. Click the icon and the extension will scan the page; come back later, click it again, and SiteDelta will highlight all changes that have occurred since your last visit. Tiny red scissors indicate places where text was removed and replaced with something else; hovering the mouse over the scissors displays a pop-up containing the previous text, which we found this to be particularly interesting on the news sites that we tried. SiteDelta has several options for configuration, including the ability to ignore case changes and number changes, and you can also set the frequency with which the extension scans for changes. We found it especially useful that SiteDelta lets you select particular regions of Web pages to scan or ignore. SiteDelta also has a Page Information tab that lets you view and copy the entirety of a Web page's text. The program can even open all of your watched pages in separate tabs all at once, making it easy to quickly evaluate all of the pages you're tracking. Overalll, we found SiteDelta to be an interesting and useful addition to Firefox, and we recommend it to anyone who needs to keep an eye on Web page changes.
SiteDelta installs and uninstalls without issues.