What is the difference between the full and basic list? 🔗

The Basic list is a smaller, less comprehensive variant of the full list, which focussus mainly on Ads, (Mobile) App Ads

The Full list blocks: Ads, (Mobile) App Ads, Phishing, Malvertising, Malware, Spyware, Ransomware, CryptoJacking, Scam ... Telemetry/Analytics/Tracking (Where not needed for proper functionality)

Use the full list only if your adblocker can handle it (due to it's size).

The Full list already blocks all the domains Basic does, thus when using the Full list, it's useless to also add Basic.

What is the difference between abp.oisd.nl, dbl.oisd.nl, hosts.oisd.nl, ...? 🔗

Syntax. Unfortunately not all adblockers handle the same syntax, so choose the one that's right for your adblocker.

hosts?.oisd.nl is bigger and has more entries than abp.oisd.nl. Does abp.oisd.nl block less? 🔗

No. If anything, abp.oisd.nl blocks more, since it also blocks subdomains by default.

This is also one of the main reasons I recommend using AdGuard Home (with https://abp.oisd.nl) instead of Pi-hole (or any software that only works with the "domains" or "hosts" -syntax)

How often is the list updated? 🔗

The quick answer is; At least once every 24 hours.

It really depends on if there are changes in the source lists, and when false positives get removed from the oisd list.
A good guess from me would be:

oisd full: at least once every 24 hours
oisd basic: updated daily, but don't be surprised if there are some days it's not
oisd extra: updated only when a domain get's removed from oisd full that's listed in the default lists from either Pi-hole or AdGuard (Those will get added to extra)

How often is the list pruned of domains that no longer exist? 🔗

Twice a month

The 'wildcard'-syntax lists (all lists besides dbl and hosts) contain domains which by themself do not resolve (example: ad.xiaomi.com), but it's subdomains DO resolve (eg; zeus.ad.xiaomi.com, track.ad.xiaomi.com, sdkconfig.ad.xiaomi.com, log.ad.xiaomi.com, globalapi.ad.xiaomi.com, e.ad.xiaomi.com, api.ad.xiaomi.com).
So by listing only one domain (even if it doesn't resolve itself), it blocks access to all subdomains, so they don't have to be listed.

I have a domain that should be listed, can it be added to oisd? 🔗

Quite possibly

I stopped manually adding domains to basic/full as it is too time consuming and quite risky (I don't want to be the cause of breakage), but you can contact any of the included lists and have them include it. Once they include it should get included in oisd as well.

On the other hand; If you know of any NSFW domains not blocked by the oisd nsfw list, you can use this form to report/add them.

I know a blocklist, can it be added to oisd? 🔗

Quite possibly

First check here. I may already know about it.
If it's listed on that page, and it's not included, please read Why is list "X" not included?
It's not on there? Please let me know!

Why is list "X" not included? 🔗

If you find a blocklist that known to me, but not included;
That is because it doesn't pass the oisd-"inclusion test".

Reasons for this;

- It's a combination of other blocklists, or
- it's too old and no longer maintained, or
- it's a duplicate (or mirror) of another list, or
- it malformed and doesn't make sense, or
- it contains too many false positives, or
- it contains one (or more) domains that blocks something that should never be blocked, or
- it's syntax is not supported (yet).

Most of the time the reason why a blocklist is not included into oisd is because "it contains one (or more) domains that blocks something that should never be blocked".

Here are some examples; apple.com, microsoft.com, google.com, facebook.com, amazon.com, login.live.com, youtube.com, reddit.com, adidas.com ... you get the point.

There's a reason as to why I won't be disclosing the full list of those domains;

Some years ago, a blocklist maintainer asked me why his list wasn't included. (It wasn't included, because it included a domain as stated above).
Of course I was willing to help, and told him all the issues (that I was aware of) regarding his list.
He fixed them all, and as a result, his blocklist was included.

Within hours, false positive reports rolled in, all pointing to his list... and I was forced to pull it.

So.. lesson learned. If a list is that bad, it most probably has way more bad entries (that I don't know of yet), and letting them know the issues (that I'm currently aware of) to get it included, will have a too high risk of introducing lot's of false positives into oisd.


All non-included blocklists because of this ARE re-checked daily, so if their reasons for not being included DO get fixed (by other means of ME letting them know), they will get included automatically.

I'm using the oisd blocklist but I still see ads? 🔗

There can be different reasons for this:
- Maybe the ads are 'baked-in' (Baked-in ads cannot be blocked)
- Maybe the domain is also being used for legit (non-ad) content (Blocking the domain would also block the legit content.)

Also read; Do you have any other recommendations besides this blocklist?.

Do you report false positives upstream? 🔗

No. With the amount of lists included, that's near impossible.
The reasons for removal are also often not in line with the original blocklist.
False postives (and 'dead' domains) are publicly viewable per-list on the 'included lists'-page, so if you are a blocklist maintainer (and your list is being included in oisd), or you are just curious, it's easy for to check which domains are not being used by oisd, and why ;)

Should I leave the default lists enabled? 🔗

When using this list in browser add-on blockers (eg. uBlock Origin, Safari Filters);
Yes definitely, as this is not meant to be a replacement for it's default lists.

When using this list in network based DNS blockers (eg Pi-hole, AdGuard Home); I'd say NO

Where the default lists are known to break stuff (shopping referral links, google shopping, video playback, etc), the whole idea of this blocklist is to have ZERO breakage, That's why if you share my opinion on having a functional internet experience as first priority and an ad/tracker/etc blocking as second, the answer is NO.

If you don't share that opinion, the answer will be YES, please DO keep the defaults enabled, or use the oisd extra add-on alongside oisd full/basic.

Does oisd block youtube ads? 🔗

No. Youtube ads cannot be blocked by DNS based blockers (where oisd is made for)

Adguard article
pi-hole.net topic

- Use your browser, with add-on adblocker like uBlock Origin (Desktop, mobile)
- Newpipe (Android)
- https://kb.adguard.com/en/android/solving-problems/youtube-ads (Android)
- Youtube Premium.

So as impossible as you now know they say it is, there still exist a bunch of lists that DO claim to block youtube ads. I'll list them here so you can try them as you please;


Is there a list of domains that are being actively excluded? 🔗

Yes. Domains that are listed in included blocklists but are excluded from oisd, can be found here.

Will you open source the project? 🔗

I combine lists, remove domains that do not resolve, remove false positives, and the remainder is the list.
It's a list of domains, not software which potentially could have a backdoor.
Let's not overcomplicate things.

Do you have any other recommendations besides this blocklist? 🔗

Yes. This is a domain blocklist, designed to be used in a network wide DNS based ad-blocker (Eg. Adguard Home, Pi-hole). Since it cannot block youtube ads, hide ad-placeholders, or ads being served from the same domain as the wanted content, a browser add-on ad-blocker (Eg. uBlock Origin or the AdGuard Browser extension) is recommended.

What does oisd stand for? 🔗

Organized Intelligence of Suspicious Domains [source]

But seriously; When a friend claimed a domain name (poiasd.nl), short and untaken..(Btw: types really neat on a qwerty keyboard).. I "beat" him by 2 characters. Later decided to use it for this project.