Block and prevent trackers
Almost every website you visit loads invisible trackers in the background. These trackers make website load slower and collect your behavior, history and interests. If a third party service like Vimeo is integrated in a website it automatically loads more trackers. So the ad of one service can trigger new trackers again.
UltraBlock manually maintains a library with common third-party services (mostly trackers). For each service we maintain a list with all hostnames used by that service. This way UltraBlock knows what services are unnecessary and which ones are not. Every day, when you launch Chrome, UltraBlock will update it's local library to the latest version.
Status: Blocked
When you visit a website Ultrablock will check what services are going to be loaded in the background. If a service is marked as 'unnecessary' in the tracker library then UltraBlock will block all requests to the hostname of that service. Because your browser will not request the tracker the website will load faster and your data will stay safe. In the pop-up we indicate what services are 'blocked' by displaying the word 'blocked' behind the name of the service (if turned on).
Status: Prevented
When UltraBlock is turned on it will automatically block all unnecessary services. Some services (mostly ads) trigger extra trackers to load in the background. For example: a website that you visit loads 4 ads and these ads load 13 trackers again themselves. UltraBlock keeps a list with all services that are loaded on popular websites by tracking these websites. When you visit a popular website UltraBlock will show you how many services it detected even if you would not have been using UltraBlock. Services that we know would have loaded in the background are displayed as prevented. This gives you a great overview of how effective UltraBlock really is and what trackers the website is using.
Status: Loaded
When UltraBlock is turned off it will allow all services. This is great when you want to see what trackers and third-party trackers a website loads. Services that are loaded in the background are displayed as loaded. Please keep in mind that if you turn off UltraBlock you will not be protected agains trackers.