How to Block Adult Sites on Windows 11 (All Browsers)

Windows 11 has no single “block adult sites” switch. The practical options are Microsoft Family Safety content filters (free, but fully effective only in Edge), a DNS filter such as Cloudflare for Families or OpenDNS FamilyShield (free, every browser and device), the hosts file (free, manual), or a system-wide app filter such as ScreenRhythm Pro. No single layer is a guarantee; two layers are better than one.

This guide is written for a parent who wants to reduce the chance of accidental exposure, not to build a surveillance system. It covers what each method actually does, how to set it up, and where a determined child can still get around it.

Method 1: Microsoft Family Safety content filters (free, Edge)

Family Safety can block adult content, turn on safe search and block specific sites. It requires Microsoft accounts for the parent and the child, and it filters web content fully only in Microsoft Edge.

1. Set up the family group. Sign in at account.microsoft.com/family and add the child. The family account guide covers the details.
2. Sign in on the child's PC. Use the child's Microsoft account in Windows and keep it a Standard user.
3. Open Content filters. At family.microsoft.com select the child → Content filters → Web and search.
4. Turn on filtering. Enable “Filter inappropriate websites and searches”. Add specific sites to the blocked list if needed.
5. Test in Edge. Open a known adult site as the child. Then check Chrome or Firefox — they are usually blocked as apps, not filtered.

Method 2: A DNS filter (free, every browser and device)

DNS filtering blocks domains before the browser connects. It works in every browser and in many apps, because it happens below the browser. The easiest setup is on the router, which covers every device in the home.

1. Choose router or PC. Router-level covers phones and tablets too. PC-level covers only this computer.
2. Set the DNS addresses. On Windows: Settings → Network & internet → your adapter → DNS server assignment → Edit → Manual → IPv4 on.
3. Flush the cache. Run ipconfig /flushdns in Command Prompt.
4. Test two browsers. Open a known adult site in Edge and Chrome. Both should fail.
5. Add a second layer. Keep the child on a standard account and block VPN apps if bypassing is a concern.

Method 3: A system-wide app filter (every browser, one switch)

A dedicated filter runs as a Windows service, so the child cannot turn it off from a browser and it applies to every browser. ScreenRhythm Pro uses a DNS-based filter with four categories: adult content, gambling, ads and trackers, and social networks.

• Good for: a family that wants one switch for the main categories in every browser, without managing a router.
• Not for: custom URL lists or per-site rules. ScreenRhythm does not offer a custom blocklist; use the hosts file or Family Safety for specific sites.
• Free plan: the filter is part of Pro. The free plan covers time limits, breaks, schedule and screen lock.

Method 4: The hosts file (free, manual)

The hosts file can block specific domains in every browser. It is useful for a handful of sites, not for filtering the open web.

1. Open Notepad as administrator.
2. Open C:\Windows\System32\drivers\etc\hosts.
3. Add one line per domain: 0.0.0.0 example.com and 0.0.0.0 www.example.com.
4. Save and run ipconfig /flushdns.
5. Test in every browser. A standard user cannot edit the file without administrator rights.

Limitations: manual, no categories, no automatic updates, and a child with administrator rights can edit it. Use it as a supplement, not the main filter.

Which method should you use?

What actually works in practice

• Use two layers. A router DNS filter plus a standard Windows account closes most accidental exposure and most casual bypasses.
• Keep the child off an administrator account. An administrator can change the DNS, disable the filter or install a VPN.
• Explain the rule. “This is blocked because it is not for kids” is easier to accept than a surprise error page.
• Check the other devices. A PC filter does nothing for a phone on mobile data. Router-level filtering covers more.
• Review after a few weeks. If the filter blocks a safe site for school, add an exception instead of turning the whole filter off.

Questions

ScreenRhythm is our product. We describe Microsoft Family Safety, DNS filters and the hosts file honestly, including their limits. No filter replaces parental supervision. This article is general information, not legal advice.