9.9.9.9 provides a first-party tool to test domains against their block list https://quad9.net/result/ https://quad9.net/result/ and there is also 9.9.9.10, w

9.9.9.9 provides a first-party tool to test domains against their block list https://quad9.net/result/ https://quad9.net/result/ and there is also 9.9.9.10, which does not perform any blocking (if it does, then no one has noticed that, which is unlikely)