For the sake of the example, let's add AdGuard DNS filter. You can add any DNS filter or hosts file, the instruction will be the same for all of them. You can add multiple DNS filters and/or hosts files at the same time, but you can't use multiple DNS servers at once.You can use any DNS server at your discretion and you are not tied up to a specific blocking server.The second option takes a bit more time to set up but has several advantages: Add a DNS filter/hosts file that will block ad and tracking domains, e.g.Enable AdGuard DNS server ( Settings → DNS protection → DNS server → AdGuard DNS).Now, if your purpose is to block ads and trackers system-wide, you have two options: To do so, open AdGuard for iOS settings → DNS protection and switch it on. First, you have to enable DNS protection. On iOS, the only way to block ads and trackers system-wide is to use DNS filtering.

This article will tell you how to set it up on your iOS device. System-wide filtering means blocking ads and trackers beyond the Safari browser, i.e. How to configure system-wide filtering with AdGuard for iOS About system-wide filtering

Ad guard ios