DEV Community: Mamori

How to Block Adult Websites on a Samsung Galaxy: What Each Setting Really Does

Mamori — Mon, 09 Nov 2026 12:25:41 +0000

Some Galaxy settings filter adult sites. Several popular ones only look like they do. Here is which is which, from Samsung's and Google's own pages.

Search for "how to block adult websites on Samsung" and you get a long list of settings to switch on. The trouble is that many of them were never built to filter websites. You turn them on, feel protected, and then find the same sites still load.

This article sorts the Galaxy settings people most often mention into two groups: the ones that actually filter adult sites, and the ones that do something else. Every claim below comes from Samsung's, Google's or the DNS provider's own help pages, linked at the end.

Settings that do NOT filter adult sites

These are useful features, but none of them blocks adult websites. It is worth knowing that before you rely on one.

Secret mode in Samsung Internet. Secret mode stops the browser keeping your history and cookies. It is a privacy feature. It does not block or unblock any site.

Smart anti-tracking and pop-up blocking. Both live in Samsung Internet's privacy settings. They deal with trackers and pop-ups, not with what kind of site you visit.

Ad blockers and content blockers for Samsung Internet. Samsung's developer documentation says the browser "does not provide the contents blocking filters" itself, and that these filters come from separate apps. Samsung describes their purpose as cutting visual clutter, data use and loading time. They are aimed at ads, not adult content.

Digital Wellbeing. Settings > Digital Wellbeing gives you screen time figures and app timers. That helps if the problem is hours lost, but it does not filter websites.

Google Play content restrictions. These limit what can be downloaded from the Play Store by rating. Google notes they apply only to the device you set them on, and that restricted content can still appear through search or a direct link. They do nothing to websites.

If you have switched on any of these and wondered why nothing changed, this is why.

Settings that DO filter adult sites

1. Private DNS with a family filter (covers the whole phone)

This is the most effective free option, because it works below the browser. Every time your phone opens a website, it first looks up the site's address. A family-filter DNS provider simply refuses to answer for adult domains, so the site never loads.

Samsung's support page gives the path:

Swipe down and tap the Settings (gear) icon.
Tap Connections, then More connection settings, then Private DNS.
Choose the option to enter a provider hostname, type the hostname and tap Save.

Samsung's page does not list hostnames. Cloudflare publishes one for blocking malware and adult content: family.cloudflare-dns.com. Cloudflare says Private DNS needs Android 9 or later.

Because it is a phone-wide setting, it applies to Samsung Internet, Chrome and other apps that use the phone's normal DNS. Three limits are worth knowing:

Some browsers and apps have their own secure DNS setting, which can bypass the phone's.
Some work, school and public Wi-Fi networks block encrypted DNS, so the connection may fail on those networks.
Anyone holding the phone can set Private DNS back to Off in a few taps.

After setting it up, test it: open a site you expect to be blocked in each browser you use.

2. Google SafeSearch (covers Google results only)

SafeSearch filters explicit results in Google Search. You can set it to Filter or Blur. Google is clear that it covers Google Search only, not other search engines or the websites themselves. It is a good extra layer, not a block on its own.

3. Family Link (for a child's phone)

For a child's Galaxy, Samsung points to Google Family Link: Settings > Digital Wellbeing and parental controls > Parental controls, then sign in to the child's Google account.

In Family Link, Chrome has three site settings: "Allow all sites", "Try to block explicit sites" and "Only allow approved sites". Google's own page adds two honest warnings: "No filter is perfect", and a child "may also have access to other browsers where Family Link settings for Chrome won't apply." On a Samsung phone, Samsung Internet is exactly that other browser, so pair the Chrome filter with Private DNS, or block the other browsers as apps.

Why the working settings still fail for adults

For a parent setting up a child's phone, the methods above are a solid start. The parent holds the password, the child does not.

For an adult blocking for themselves, the weak point is different. Every working setting above can be switched off by the same person who switched it on, and it takes seconds. The moment you most want to turn the filter off is the moment it most needs to hold. That is not a character flaw. Settings menus are designed for convenience, not for self-restraint.

Two things help:

Layers. Private DNS plus SafeSearch is harder to get around than either alone.
Distance from the off switch. A delay, a long phrase you have to type, or a PIN that someone you trust holds. Even a few minutes of friction is often enough for an urge to pass.

Where Mamori fits

We make Mamori, so take this section as what it is. Mamori is an adult content blocker built for adults who want to stop viewing adult content on their own phone. On Android it filters site lookups on the phone itself, using Android's VPN service with no remote VPN server, and blocks more than 2.5 million adult domains across every browser and app, including many Japanese sites that Western filters miss.

The main feature is the lock. When you switch protection on, you choose what stands between you and the off switch: a cooldown timer, a phrase, or a PIN a trusted person can hold. While protection is on, it cannot simply be uninstalled. When you switch it off, everything is off, and the app uninstalls normally.

Honest limits: Android allows one VPN at a time, so another VPN app can take Mamori's place. And no app replaces support from people you trust. For a child's phone, Family Link should be the base layer.

If you want the full, step-by-step version for your phone, these guides go deeper:

Mamori is on Google Play and the App Store with a 7-day free trial: mamoriblocker.com.

Sources

Samsung US Support, Connection options on Galaxy (Private DNS path): https://www.samsung.com/us/support/answer/ANS10002546/
Samsung Developer, Samsung Internet for Android overview (content blockers): https://developer.samsung.com/internet/android/overview.html
Samsung US Support, Secret mode in Samsung Internet: https://www.samsung.com/us/support/answer/ANS10010475/
Samsung US Support, Family Link on Galaxy: https://www.samsung.com/us/support/answer/ANS10003399/
Cloudflare, Set up 1.1.1.1 on Android (Private DNS, family.cloudflare-dns.com): https://developers.cloudflare.com/1.1.1.1/setup/android/
Google For Families Help, Manage your child's browsing in Chrome: https://support.google.com/families/answer/7087030
Google Play Help, Parental controls on Google Play: https://support.google.com/googleplay/answer/1075738
Google Search Help, SafeSearch: https://support.google.com/websearch/answer/510

How DNS filtering works on a phone, and where it stops working

Mamori — Mon, 09 Nov 2026 10:20:54 +0000

Adapted from the Mamori guide DNS filtering on Android, step by step. Vendor details were checked against Google, Cloudflare and CleanBrowsing documentation.

A lot of content filtering, from parental controls to company networks, comes down to one small step: the DNS lookup. Understand it and you can see what a filter can block, what it cannot, and how it gets bypassed. The example here is blocking adult sites on a phone, but the same mechanics apply to malware or ad domains.

The lookup a filter hooks into

When you open a website, your phone first asks a DNS resolver to turn the name, such as example.com, into an IP address. Only then does it connect.

A filtering resolver keeps a list of domains by category. When a lookup matches a blocked category, it does not return the real address. The connection never starts, so the page never loads.

This has two useful properties:

It covers every app, not just one browser. Any app that uses the system resolver goes through the same check.
It is cheap. There is no need to inspect page content, so it adds almost no work for the phone.

It also has one built-in weakness. It only sees names. It cannot see what is on a page, so a site that is not on the list yet, or adult content hosted on a large general site, can slip through.

Option 1: a public family resolver

The quickest setup uses a public resolver that already filters. Two common free ones:

Cloudflare 1.1.1.1 for Families. The version that blocks malware and adult content uses the hostname family.cloudflare-dns.com, or the IP addresses 1.1.1.3 and 1.0.0.3. The malware-only version (security.cloudflare-dns.com, or 1.1.1.2 and 1.0.0.2) does not block adult content.
CleanBrowsing Adult Filter. Hostname adult-filter-dns.cleanbrowsing.org, IPv4 185.228.168.10 and 185.228.169.11. It blocks adult sites and enforces SafeSearch on Google and Bing. It does not block proxies, VPNs or mixed-content sites. CleanBrowsing's stricter Family Filter does block those. The free tier is throttled and has limited settings.

On Android 9 and later, you set this system-wide with Private DNS. Open Settings, then Network & internet, then Private DNS. Choose "Private DNS provider hostname", enter the hostname with no https://, and save. On some phones the setting sits under an Advanced heading. If you can't find it, search Settings for "Private DNS". Private DNS uses DNS over TLS, which is why it takes a hostname and not an IP address. Cloudflare notes that once it is set, the phone uses that resolver on every network, mobile data included.

iPhone is different. Cloudflare's own page says a manually set DNS server only applies to the Wi-Fi network you are on and does not work on mobile data. That is why iPhone filters usually install a profile or use Apple's Screen Time web filter.

Option 2: an on-device filter using the VPN slot

Many blocker apps on Android, Mamori included, ask for the VPN permission. They do not do this to send traffic to a remote server. They do it because Android's VpnService API is the supported way for an app to see the phone's DNS traffic.

The common pattern works like this:

The app creates a local VPN interface and tells Android to use a DNS server address that routes into that interface.
DNS queries arrive at the app on the phone itself.
The app checks each name against its blocklist. Blocked names get no usable answer. Allowed names are forwarded to a normal upstream resolver, and the answer is passed back.
All other traffic carries on as normal.

Done this way, nothing leaves the phone that would not have left anyway, and no browsing log has to exist. The trade-off is set out plainly in Android's developer documentation: "There can be only one VPN connection running at the same time. The existing interface is deactivated when a new one is created." So if you turn on a privacy VPN, or install a second blocker, the filter is quietly switched off. Android also lets the user stop any VPN app from the VPN screen in Settings.

Where DNS filtering stops working

Every DNS filter, whatever the setup, shares the same limits:

The user can undo it. CleanBrowsing says anyone with access to the network settings can change the DNS server, and on most systems it "takes less than a minute".
Browsers can bypass it. Chrome and Firefox have their own encrypted DNS setting. When it is on, the browser can resolve names itself and skip the system filter. Google notes that Chrome's secure DNS cannot be used if the device is managed or parental controls are on.
Other software may not follow it. A VPN, or an app that does its own DNS, may not use the choice made in Settings.
Names, not content. New domains and mixed-content sites get through until a list catches up.

Making it stick

The filter is the easy part. The hard part is the moment when the person who set it up wants it off. So the useful extras add friction: a lock someone else holds, a delay before switching off, and protection against simply uninstalling the app.

Mamori is built around that layer: a filter for 2.5M+ adult domains, plus a cooldown timer, phrase or PIN lock you choose before you need it. When protection is off, everything is off and the app uninstalls normally. It is meant as a lock you set on purpose, not a trap.

The full step-by-step guide, with the sources, is here: DNS filtering on Android. For a side-by-side look at Screen Time, DNS, VPN-based apps, extensions and router filters, see blockers compared.