Q. What is it?

URLFilterService is an internet filtering application running on Microsoft Windows operating systems.

Q. How does it work?

There are two working modes:

MODE man in the browser - this mode works by hooking and detouring specific  api calls inside Internet Explorer and Microsoft Edge.

MODE DNS filter - it works like a DNS resolver and can be used locally (if you want to filter any kind of software running on your computer) and remotely (serving many computers/devices on a local network). This mode is disabled by default and requires a medium IT skill level to be set up.

In both modes, using a list of domains and urls sorted in categories, it works by applying filter rules allowing or denying access to requested objects. There are many lists over the net, the ones used by URLFilterService are:

but others can be easily added (send me an email, see below for mail address). If you want you can  extend items on the lists as you like or build a custom one from scratch.

Q. What are supported systems?

It should work on every recent x86 and amd64 system. I tested and found it working on:

  • Windows 7 professional, 32 bit;
  • Windows 10 professional, 64 bit.

Please note: because code injection works by checking static patterns inside function calls, any system could stop working after a system update. Because I can't check every system version out there, whenever you find yourself with a non working version send me an email and I'll try to make things working again.

Q. Can you add my language to Interfaccia.exe and Identita.exe?

This can be easily done translating English.txt and saving the new file inside languages directory. Send me the translation if you like and I'll put it into next releases.

Q. Why do I have to use this software?

I think that every Windows pc should have an antivirus installed, a personal firewall and obviously an internet filter. If you don't like the "look and feel" of URLFilterService, don't trust me at all or don't find UFS suitable for your needs, I'm pretty sure you can find one for you on this list.

Q. Is it safe to use your software?

If you download URLFilterService from urlfilterservice.net mostly is, but I can't guarantee anything. I must warn you:  if not used properly you can block useful applications like system updates and smartscreen protection. Use at your own risk.

Q. My antivirus/smartscreen filter says there's a virus in URLFilterService, why?

I guess this is because of its nature: hooking and detouring are suspicious activities, and the code is not digitally signed. I will not ask you to trust me, I'll ask you to trust your security suite vendor submitting them a copy of URLFilterService for antiviral analysis.

 Q. Why did you remove system wide hooks?

I found it to be too invasive and dangerous to manage for non IT skilled people. System hook code is always "there" but I don't plan to make it available to others anymore. If you need a system wide filter I suggest you to setup UFS DNS filter.

Q. I opted to block images (or a specific MIME type) in MITB mode but I still see many of them, why?

Did you whitelisted the site? If the answer is no maybe browser's cache is taking on the page objects. To remove images and/or anything else, empty browser's cache first and then reload the page.

Q. I disabled javascript in MITB mode but i can see scripts running, why?

Always check if site has been whitelisted and empty browser's cache first.  Javascript can't be disabled in the latests versions of Windows 10, and EDGE has no option to disable them either. The only way I found to block scripts in EDGE is by checking HTML pages MIME type. Technically speaking: if the script is inside the main page UFS can't block it, but if it is located in a different HTML page which has to be side loaded and has the expected MIME type, it won't be executed.

Q. I just blocked a host/domain but it still get resolved, why?

If the host has been previously resolved then it should be cached by the system: empty dns cache opening an elevated command prompt and using the command ipconfig.exe /flushdns.

Q. What is HSTS?

The best answer I can think of is available on wikipedia. HSTS can be used for tracking people but can also be used for legitimate reasons. In my case I've HSTS enabled on the pc I use for home banking and to buy on marketplaces, but it is disabled on the one I use to surf the web for fun.

Q. Host, domain, url, partial url, ip... Can you explain me the difference?

I'll do it using the url of the above wikipedia article


en.wikipedia.org is the host;

wikipedia.org is the domain;

org is the top level domain;

en.wikipedia.org/wiki/HTTP_Strict_Transport_Security is the complete url;

everything that starts form en.wikipedia.org/ and is not the complete url, is a partial url;

nslookup en.wikipedia.org gives as result  which is the ip, at the time of writing, of en.wikipedia.org.

Q. What is the sequence order of  UFS site check algorithm?

The following is the check sequence: url, host, domain, tld.

Q. What about user privacy?

I do not collect any kind of user data. Everything about UFS is located on your computer. Every time you open up Interfaccia.exe, urlfilterservice.exe phone home to check for a program update; block www.urlfilterservice.net host to avoid it.

Q. How much does UFS costs?

It's free, if you find this application useful please consider making a donation (see download page for paypal link). You can freely use it for whatever reason and in whatever environment, but you can't absolutely charge anyone for it.

Q. How do I login to Interfaccia.exe?


Password: 1234

Q. I have many questions not covered by this F.A.Q. can I contact you?

If questions are related to usage please have a look at video guide and help sections first. Still having unanswered questions? Feel free to contact me by email, but please don't complain if you get a slow answer or no answer at all, this is  just a hobby and i don't offer 24/7 support.