Adhole is a DNS that protects your devices from unwanted content, such as advertisements and tracking, without installing any client-side software. Instead of installing adblockers on every device and every browser, you can use Adhole DNS once on your network and it will protect all of your devices. Because it works differently than a browser-based ad-blocker, Adhole also block ads in non-traditional places, such as in games and on smart TVs.

Yes. DNS queries together with their originating client IP address are stored for 24 hours to protect against DNS amplification attacks. This is an automated process and requires no human interaction. I.e. I will NOT be sniffing through the logs.

DNS queries are stored in the pihole.log and FTLDNS database. After 24 hours, logged DNS queries are deleted from disk and are not included in any backups.

Rest assured that I will never sell or share your data with any third party. I have no desire to impose on you and zero interest in trying to do anything with your private details.

All instances use their own, local, recursive DNS server, powered by unbound. The reason for that is simple:

After applying the blocking lists, requests made by the clients are forwarded to configured upstream DNS server(s). However, as has been mentioned by several users in the past, this leads to some privacy concerns as it ultimately raises the question: Whom can you trust? Recently, more and more small (and not so small) DNS upstream providers have appeared on the market, advertising free and private DNS service, but how can you know that they keep their promises? Right, you can't.

Furthermore, from the point of an attacker, the DNS servers of larger providers are very worthwhile targets, as they only need to poison one DNS server, but millions of users might be affected. Instead of your bank's actual IP address, you could be sent to a phishing site hosted on some island. This scenario has already happened and it isn't unlikely to happen again...

When you operate your own (tiny) recursive DNS server, then the likeliness of getting affected by such an attack is greatly reduced.

Source: https://docs.pi-hole.net/guides/unbound/

All instances use oisd's meta blocklist.
More information about this massive blocklist can be found here.

Yes, Adhole passes the DNS Nameserver Spoofability Test by GRC, which checks for Cache Poisoning.

dns-cache-poising-adhole

After configuring your device to use Adhole, navigate to dnsleaktest.com and run a standard (or extended) test. ONLY *.adhole.org should show up as hostname(s) the results table, like shown below.

dnsleaktest-adhole

See the details on the DNS Servers page. All instances are placed on fast uplinks in professional data centers.

My name is Freek. I operate this DNS service as an individual with my own money. If you have questions or comments, please see the contact page.

No. This service is provided based on best effort.
Additionally, it's provided without any warranty and I renounce liability for any claim, damages or other liability arising from the use of this service.

Ideally, no. Adhole is intended to be used by the prosumer. Recently, the project has been a victim of its own success, with entire internet cafes pointing their DNS to Adhole, causing performance issues for everyone. Hence, I've decided to put a rate limit in place, in order for the service to remain available for the intended audience. This generous rate limit should be more than sufficient for the average power user. However, should you encounter intermittent connection issues, please do let me know to verify what’s causing it.

For those of you with a large (enterprise) network, I suggest setting up your own, local, AdGuard or Pi-hole instance. This way, you will benefit from near zero latency, as well as having more control over your DNS queries.

YouTube serves (most of) theirs ads from the same domain they serve their video content from. Hence it's (almost) impossible for a DNS based adblocker to block YouTube ads because you cannot just block the subdomain, as it will also break video playback.
There are some hacky solutions out there, but none are stable and guaranteed to work. Most of them just break YouTube playback and it's really a cat and mouse game.

I suggest using uBlock Origin as browser plugin to block YouTube ads instead. If you own Android Smart TV, I recommend taking a look at 'Smart YouTube'. It's basically an (open source) YouTube client with built-in (client side) adblocking.

All Adhole instances are deployed using Ansible. The code to do so is open source and can be found on my Github profile: https://github.com/Freekers/ansible-adguard

However, please do note that I won't add any instances to the project that are not under my control, as I cannot vouch for them.