Q. What is it?

URLFilterService is an internet filter for Microsoft Windows operating systems (X86/AMD64). Its filtering rules are based upon host/domains/urls sorted in categories where you choose which ones to block.

Q. How does it work?

There are two working modes:

MODE "man in the browser" - this mode injects filtering code directly into Internet Explorer and Microsoft Edge and works only on processes started on  local computer. This mode doesn't support any other application.

MODE "DNS filter" - it works like a DNS resolver and can be used to filter requests on a single computer and/or on a local network.

URLFilterService actually use web categorizations by:

If you want you can  extend the lists as you like or build a custom one from scratch.

Q. Does MITB mode support EDGE Chromium?

No, it doesn't.

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.


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 into the languages folder. Send me the translation if you like, I'll put it into next releases and give you credit.

Q. Is it safe to use your software?

If you download URLFilterService from urlfilterservice.net mostly is, but I can't guarantee anything. Always check sha256 hash to be sure the file you downloaded has not been altered. 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. I opted to block images (or any other 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 response page MIME type. Basically speaking: if the script is inside the main page UFS can't block it, but if it is located in a different page which has to be side loaded and has one of 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 could have been 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 to track peoples 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 (MITB mode only), host, domain, tld.

Q. I whitelisted a specific url on a blocked site but page don't load, why?

Do you use dns filtering all together with MITB mode? If host or domain are blocked then there's no way the url will load because dns resolving comes first.

Q. What about user privacy?

I do not collect any kind of data except for this web server logs that are needed for security purpose. Everything about UFS is located on your computer. Every time you open up Interfaccia.exe, urlfilterservice.exe phone home to check for program update; block 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 to me and i don't offer 24/7 support.