Author here, I added this now: https://evilbit.de/dns-resolver-guide2.html#speedtest Only works for DoH though.

Clone this repo [1] and then edit the domain names and resolvers to your liking. It will be something close to what you might be looking for.

[1] - https://github.com/cleanbrowsing/dnsperftest

I run an instance of smokeping locally for this purpose. It pings a variety of DNS servers (including my ISPs DNS) and several of the top websites. I periodically update my local DNS server’s upstream accordingly.

All the big DNS servers are in the 5-6ms range for me, but that hasn’t always been the case. My ISPs DNS is about the same but with crazy variance and spikes of up to 50ms, even though they should be able to be the fastest.