Trackly is described as 'monitors web pages and tells you when they change. Beautifully!' and is an website in the OS & Utilities category. There are more than 10 alternatives to Trackly, not only websites but also apps for a variety of platforms, including Windows, iPhone, Mac and Android. The best alternative is Update Scanner, which is both free and Open Source. Other great sites and apps similar to Trackly are Visualping (Freemium), Wachete (Freemium), WebSite-Watcher (Paid) and ChangeMon.Com (Paid).
Sites Watcher checks web pages that interest you for changes. When changes are found, Sites Watcher will show you current page version with highlighted updates. As well as that, you can see previous web page version and current page version from internet.
Versionista is an online service that alerts you when a Web site changes. It shows you what's been added & removed to any Web page. It records a full page screenshot, and lets you use powerful inclusion/exclusion filters.
Fluxguard uses Google headless Chrome to monitor entire sites for changes. It provides 3 different levels of change monitoring, pixel change detecting comparing screenshots, code-level comparison of the rendered DOM, and extracted text comparison.