Short answer: You can block a lot of adult content on Android for free. Turn on Google SafeSearch, set a family-filter Private DNS hostname (Settings > Network & internet > Private DNS, or on Samsung, Settings > Connections > More connection settings > Private DNS), and use Google Play content limits. These work, but each one can be switched off in a few taps, which is the weak point when the urge hits. Below are the steps, their limits, and how to add a lock.
Version note: Google, Samsung and the DNS providers publish steps for Android 9 and later. Samsung's own pages say Family Link setup works on One UI 2.0 or later, and Samsung account parental controls need One UI 5.1 or higher. The pages we checked do not name every Android or One UI release, and menu names shift between versions. If yours look different, use the search box in Settings.
SafeSearch filters explicit results in Google Search. On Google's SafeSearch page you choose Filter or Blur (Off turns it off). Google says it covers Google Search only, not other search engines or websites, and that a lock icon means the setting is managed by someone else, such as a parent in Family Link or a network administrator.
Limit: on your own account you can switch it off again at any time.
This limits what you can download or watch from the Play Store. It does not filter websites.
Google notes that restrictions apply only to the device you set them on, apps installed earlier stay accessible, and restricted content can still show up in search results or through a direct link. Deleting the PIN turns Play restrictions off.
Private DNS sends your phone's website lookups through a provider that refuses to resolve adult domains. It works in every browser and app that uses the system DNS, on Wi-Fi and mobile data. Private DNS is available on Android 9 and later.
Stock Android (per the Cloudflare and CleanBrowsing guides):
family.cloudflare-dns.com (Cloudflare's setting for blocking malware and adult content)family-filter-dns.cleanbrowsing.org (CleanBrowsing's free Family Filter)Samsung Galaxy: Samsung's support page gives the path: swipe down and tap the gear icon, then Connections > More connection settings > Private DNS, choose an option and tap Save. Samsung's page does not list the options themselves. CleanBrowsing's guide says the same Samsung route and the same "Private DNS provider hostname" option.
Limits, stated by the providers or obvious from the design:
For your own phone, Samsung's Digital Wellbeing helps with screen time and app timers (Settings > Digital Wellbeing). It does not filter websites. Samsung notes Digital Wellbeing cannot be removed or disabled.
For a child's phone, Samsung's page points to Google Family Link: Settings > Digital Wellbeing and parental controls > Parental controls, then follow the prompts and sign in to the child's Google account. Samsung also describes Samsung account controls (One UI 5.1 or higher) under your Samsung account, then Family, then the child's profile, where you can set web content, apps and downloads, and a PIN. We could not confirm the exact web content menu names on Samsung's page, so check that screen on your phone.
In Family Link, the Chrome filter is under Controls > Google Chrome and Web, with three choices: "Allow all sites", "Try to block explicit sites" and "Only allow approved sites". Google says no filter is perfect, and you can add your own entries under Manage sites. SafeSearch can also be locked by the parent, so the child cannot change it.
We did not verify Samsung Kids or Secure Folder on Samsung's own site, so this guide leaves them out.
Every method above has the same shape: the person who set it is the person who can undo it, and the undo takes seconds. Urges are usually short and strong. At that moment, "just turn off Private DNS for a minute" feels reasonable. There is no shame in that. It is how settings menus are built, because they were designed for convenience and not for self-restraint.
Two things help: more than one layer, and a delay or a second person between you and the off switch. Using a PIN that someone else holds on Google Play is one example of that idea.
Can I block porn on Android for free? Yes. SafeSearch, a family-filter Private DNS hostname and Google Play limits cost nothing. Their weakness is that you can undo them yourself in seconds.
Do these steps differ on Samsung? The path to Private DNS differs: Settings > Connections > More connection settings > Private DNS. Digital Wellbeing and parental controls also sit in Settings on Galaxy phones.
Will Private DNS work with a VPN? Some VPN apps may bypass Private DNS (we could not confirm this on an official page), so check after you set it up. Android also runs only one VPN at a time.
Is there a filter for a child's phone? Use Google Family Link (or Samsung account controls on One UI 5.1 or higher) as the base layer, then add Chrome and Play settings.
Mamori is an Android app built for adults who want to block porn on their own phone, with the lock as the main feature.
Honest limits: Android allows only one VPN at a time. If another VPN or blocker takes that slot, Mamori's filter can switch off, so avoid running both. No blocker replaces support from people you trust. For a child's phone, use Family Link as the base layer; Mamori is built for adults blocking for themselves.
A good setup: Private DNS and SafeSearch as a free base, a PIN on Play restrictions, then Mamori with a lock you cannot undo on impulse.
Last checked 11 Oct 2026. This guide is general information, not medical advice.