I responded to someone in comments on a post that may not get as much visibility, and wanted to share something that might help some others sail the seas but also while not sailing, too.
I referenced Quad9 DNS as probably one of the best private DNS you can use, Swiss based, no log, no tracking, no data to sell, etc. They also implement DNSSEC, DoH, DoT, QUIC, ECS (which you may or may bot want), malware blocking, content filtering, and maybe something else I’m forgetting.
Many DNS sinkhole apps, OSes, or systems can actually utilize Quad9 for your resolver while those systems also block ads. Below is my functional list of systems that I’m aware of, though I haven’t tested everything. I believe all are considered FOSS, too. If you don’t have a spare Raspberry Pi laying around, try running in HomeAssistant, Yunohost, ZimaOS (previously CasaOS), or others.
DNS sinkhole (Adblocking) apps:
Feel free to comment and add your own I’m maybe not aware of. I’m no software engineer, but I can read through some code, though not an expert, nor have combed through these personally. Usually I’ve tested/run at the recommendation of others over the years before my ban on Reddit (for shitting on AI).
Hope this helps!!


And your effort on providing the information is appreciated (I’ve already set up Quad9!).
Just one question:
What do you mean uBO can use Quad 9? Do you mean it can be set up as an alternate resolver instead of using the system? Because if so, that would be great for provisioning eg.: Firefox + uBO on corporate semi-locked platforms when I have to do so for support reasons. Is there a hidden config or something?
If you’re talking about a browser, Firefox I believe can config custom DNS, but idk about it working alongside the extension if the extension needs to use its own. For the browser, I use PrivacyBadger from EFF for cookie and tracker blocking and PortAuthority which blocks LexisNexis port scanning on sites like eBay, etc. My adblock is done through pihole. Pihole uses Quad9 for the resolver.