Mamori / Guides

Website Blocker, App Blocker or DNS Filter: Which One Blocks What

Updated

On this page
  1. The four kinds, in plain terms
  2. 1. Browser extensions and browser settings
  3. 2. Operating-system website limits
  4. 3. App blockers and app limits
  5. 4. DNS filters
  6. Quick comparison
  7. FAQ
  8. Where Mamori fits

Short answer: They work at different levels. A browser extension or browser setting covers one browser. An operating-system website limit covers what the OS applies it to. An app blocker or app limit covers whole apps, not the web pages inside a browser. A DNS filter covers the lookups that your device or network sends. Each one leaves gaps the others fill, so it helps to know which gap you are trying to close.

Version note: iPhone details follow Apple's iPhone User Guide for iOS 18 and iOS 26 (Apple's iOS 27 page for this topic no longer shows the Web Content setting). Android details follow Google's Android Help. Chrome details are for Chrome on a computer unless stated. Read on 8 Nov 2026.

The four kinds, in plain terms

  1. Browser-level tools: extensions and browser settings.
  2. Operating-system website limits: such as Screen Time on iPhone.
  3. App blockers and app limits: tools that stop or time-limit whole apps.
  4. DNS filters: services that decide which website names your device or network can look up.

1. Browser extensions and browser settings

These live inside one browser. Apple's Safari page says extensions can "block content on websites," and describes adding them in Safari from Manage Extensions. Google's Chrome Web Store page covers installing extensions in Chrome and says: "Make sure you only approve extensions that you trust."

Browser settings also count here. Google's SafeSearch page says "On Google Search, Safesearch attempts to identify and filter inappropriate content," and that its Filter setting "Blocks all explicit results." The same page says Blur "blurs explicit images" but "explicit text and links can show if they're relevant for your search."

What they cover: the browser or search engine they are set up in.

What they can miss:

  • Other browsers and apps. An extension in one browser does nothing in another.
  • Private windows. Apple says that in Safari, "Any Safari extensions you have installed that have access to browsing data are automatically turned off in Private Browsing" unless you turn them on. Check how any extension you use behaves in a private window. Our guide covers this in more detail: Private Browsing, Incognito and Porn Blockers: What Gets Around What.
  • Search settings only apply to search. SafeSearch does not stop you typing an address directly.
  • Someone can switch it off. Extensions and settings can be removed by the person who installed them.

2. Operating-system website limits

On iPhone, Screen Time can limit adult websites. Apple's page for iOS 18 and iOS 26 gives this path: Settings > Screen Time > Content & Privacy Restrictions > App Store, Media, Web, & Games > Web Content, then select Limit Adult Websites. Under Never Allow you can Add Website to block specific URLs.

Apple's iOS 27 page for blocking features or content lists content restrictions and other features, and it does not show Web Content. If you are on iOS 27, check Apple's current page or your own settings rather than relying on the iOS 18 and iOS 26 path. Our iPhone guides cover the details: How to Block Websites on iPhone: Screen Time Steps for Any Site.

What it covers: Apple's page describes this as a Screen Time setting for your device (or a child's device). It does not spell out which apps the filter applies to, so check how it behaves in the browsers and apps you use.

What it can miss:

  • It is a limit, not a guarantee. Apple's own wording is "Limit Adult Websites" plus URLs you add by hand, so check it against the sites that matter to you.
  • The passcode matters. Screen Time settings can be changed by anyone who knows the Screen Time passcode, so who holds it matters. See our guide on forgetting the passcode and who should hold it: Forgot Your Screen Time Passcode? Reset Options and Who Should Hold It.

On Android the routes vary by phone and browser, and we have not found one single official setting that covers every phone. Our guide covers the options: How to Block Websites on Android (Any Site, Not Just Adult).

3. App blockers and app limits

These work on apps. On iPhone, Apple's page says you can turn off apps under Allowed Apps & Features in Content & Privacy Restrictions. On Android, Google's Digital Wellbeing page describes App timers ("When you run out of time, the app closes and its icon dims") and Focus mode, where you choose apps to pause: "When Focus mode is on, you can't use these apps and won't get notifications from them."

What they cover: the apps you choose.

What they miss: the web. An app limit on a browser blocks or times the whole browser, not one site inside it. In our view, if your concern is a particular kind of website, an app limit is a blunt tool, and if your concern is a particular app, it is a better fit. Apps with their own built-in browsers or search are also worth checking individually.

4. DNS filters

In simple terms, a device looks up a site's address before the page loads. A DNS filter changes who answers that lookup, so a blocked name can be refused.

  • On a router: Cloudflare's router page says "Configuring 1.1.1.1 on your router applies the DNS setting to every device on your network." In our reading, that is about devices on that network, so it does not follow your phone onto mobile data or another Wi-Fi network.
  • On an Android phone: Google's page for Private DNS says the path is Settings > Network & internet > Private DNS, with options Off, Automatic or Private DNS provider hostname. It also says Private DNS "helps secure only DNS questions and answers. It can't protect anything else."
  • In a browser: Google's Chrome page says secure DNS is "turned on in automatic mode" by default and that you can select a custom provider, so a browser can have its own DNS setting that is separate from the one your device uses. Check it if a filter seems to be skipped.
  • As an app on the device: some apps set up a filter on the phone itself. Android allows only one VPN at a time, so a DNS filter that uses Android's VPN slot and another VPN cannot both run.

What they cover: any app or browser that uses the filtered lookup, for as long as the filter is active on that network or device.

What they can miss: anything that does not go through the filtered lookup, and phones that leave the network a router filter protects. Anyone with access to the settings can also change them. The setup steps are in our guides, so we are not repeating them here: DNS to Block Porn: Free Family DNS on Android, Step by Step and Secure DNS and Porn Filters: When Encrypted DNS Helps and When It Bypasses a Filter.

Quick comparison

  • Other browsers: extension or browser setting covers one browser only; OS limits and DNS filters can cover more.
  • Inside apps: browser tools do not; app blockers act on the whole app; DNS filters and OS limits depend on how the app connects.
  • Private windows: check extensions, as above.
  • Mobile data vs Wi-Fi: a router filter covers its own network only; device-level tools travel with the phone.
  • Easy to switch off: all of them, unless someone else holds the passcode or lock.

For a side-by-side of specific blockers, see our comparison: Porn Blockers Compared: DNS, Screen Time, Apps and Router Filters.

FAQ

Which one should I use?

That depends on the gap. In our view, one layer is rarely enough on its own: a common approach is an OS-level limit plus a DNS filter on the router, with an app limit for particular apps.

Is a VPN a website blocker?

No, a VPN is a different tool. Some filters use the VPN slot on Android to handle lookups, which is why only one VPN can run at a time.

Does a website blocker stop apps?

Not by itself. An app blocker handles apps; a website blocker handles web addresses. DNS and OS-level tools may reach both, depending on the app.

Will any of this stop me if I really want to get round it?

These tools add friction. They do not remove the urge, and a person with access to the settings can change them. A lock set up in advance, or a trusted person holding the passcode, adds more.

Where Mamori fits

Mamori is a newer app for iPhone, iPad and Android that tries to combine several of these layers on the phone. It blocks 2.5M+ adult sites across the whole phone, not just one browser. On Android it is an on-device DNS filter using Android's VpnService, with no remote VPN server, no logging of your browsing and nothing uploaded. On iPhone and iPad it uses Apple's Screen Time web content filter plus its own blocklist. It forces SafeSearch on Google, Bing and other search engines, lets you block specific apps, and has your own block list and allow list. Its list is built to also cover Japanese adult sites.

Before protection can be switched off, you meet a cooldown timer, a random phrase, or a PIN or passphrase, and a trusted person can hold the PIN. When protection is off, everything is off and Mamori can be uninstalled normally.

Honest limits: Android allows only one VPN at a time, so another VPN or blocker that takes the slot switches Mamori's filter off. It is built for adults blocking for themselves, so for a child's device use Screen Time or Family Link as the base layer. It has no accountability reports and does not replace support from people or a professional. There is a 7-day free trial on the monthly and annual plans, plus a one-time lifetime option.

Related guides

How to Block Apps on iPhone: Screen Time Limits and What They Cannot DoBlock apps on iPhone with Screen Time: App Limits, Downtime, Always Allowed and Content & Privacy Restrictions, with exact menus and what they cannot do. Porn Blockers and VPNs: How They Interact on Android and iPhoneDoes a VPN bypass a porn blocker? It depends on how the blocker works. Android allows one VPN at a time. What that means, plus the iPhone side. How to Block Porn on Your Home Wi-FiBlock porn on every device on your home Wi-Fi with a family DNS on your router. Free Cloudflare and CleanBrowsing steps, what it misses, how to lock it.

Sources

Last checked 8 Nov 2026. This guide is general information, not medical advice.