If you're on your phone, you can use your mobile data to try and access the site instead. If you find out that this is indeed the case, the simplest way to unblock a website is to disconnect your device from the Wi-Fi network, and use another way to access the internet. Sites which are considered inappropriate might be blocked, as might those that require a lot of bandwidth, like YouTube. For example, if you're connected to Wi-Fi at school or at work, the network administrator may restrict which sites can be accessed. Sometimes, you'll find a web page blocked due to restrictions such as a firewall for Wi-Fi networks.