Here's my take. Ads will happily eat 300ms per webpage if you allow them to load. A fast DNS is great, but an adblocking DNS will save you much more time if you're just browsing.

DNS is utilized for many things besides looking up web sites (and consequently ads on web sites). DNS was used for many things etcd was invented to solve, and still is by many. Adblocking is kidstuff; the bearded, motorcycle riding, gun-shooting, jumping out of airplanes and hanging off of rocks jackals use a "DNS firewall" (just posted this the other day): https://www.dnsrpz.info/ and Dnstap for application-level DNS logging.

Absolutely — DNS goes way beyond just resolving websites. It’s been used for service discovery and coordination long before tools like etcd came along, and still is in many systems today. Adblocking is one use case, but DNS firewalls (like RPZ) and logging frameworks such as Dnstap show how powerful DNS can be at the infrastructure level. Thanks for sharing the link — it’s a great reminder that benchmarking speed is only one piece of the bigger DNS picture.

That’s a good point — adblocking DNS can definitely save time by cutting requests before they even reach the browser. The focus here was on resolver speed and monitoring, but pairing it with an adblocking DNS is a smart way to get both performance and less clutter while browsing.

Fast DNS and adblocking DNS (or other methods, for that matter) are not mutually exclusive topics, even assuming your primary use case for DNS resolution on a given machine is web browsing.

Absolutely — fast DNS and adblocking DNS aren’t mutually exclusive. The tool here is focused on resolver speed and monitoring, but it can benchmark adblocking resolvers just as well. That way you can pick the one that balances performance with blocking, depending on your browsing needs.

I doubt that your conclusion is correct (because local DNS resolvers that consult blocklists are often surprisingly slow) but I think your theory of the matter is accurate. The raw speed of the DNS server is almost irrelevant because there are other much larger systemic performance issues at stake. For example Cloudflare does not forward EDNS to the origin, so the records it returns are suboptimal for services that use DNS-based service affinity. It doesn't make a difference to me if Cloudflare is a few microseconds faster — and by the way I sincerely doubt that this python program is observing meaningful microsecond-scale differences — because overall it makes applications slower.

Fair points — blocklist‑based local resolvers can indeed be slower, and raw speed alone doesn’t capture the bigger systemic issues. The tool isn’t trying to measure microsecond‑scale differences, but rather provide a clear comparison of resolver behavior under load and over time. Things like EDNS handling and service affinity are exactly the kind of deeper characteristics that benchmarking can help surface, so users can decide which trade‑offs matter most for their environment.