Mamori / Guides

Can a Blocker Hide Images, or Only Whole Sites? An Honest Explainer

Updated

On this page
  1. What a DNS blocker actually sees
  2. What does work on images
  3. What about tools that take screenshots?
  4. Putting it together
  5. FAQ
  6. Where Mamori fits

Short answer: A DNS-based blocker works on whole site names, so it can stop a site from loading but it cannot pick out one picture on a page you can still open, or an image inside an app. Some other tools do blur images: SafeSearch on Google, and warnings built into Apple's and Google's messaging apps. Each covers a narrow area, so it helps to know exactly where.

Version note: Checked on 9 Nov 2026 against Apple's Sensitive Content Warning and Communication Safety pages (they list iOS 17 or later for the warnings and iOS 27 for gore and violence detection), Google's SafeSearch and Google Messages help pages (the Messages page lists no Android version, so check your own app), Microsoft's Bing SafeSearch page and Cloudflare's DNS explainer. Features and menus change, so use your own device's Settings as the final word.

What a DNS blocker actually sees

When you open a website, your phone first asks a DNS server to turn the site's name into an address. Cloudflare's explainer puts it this way: "DNS translates domain names to IP addresses so browsers can load Internet resources."

A DNS filter answers that question differently for sites on its list, so the page never loads. The decision is made about the name of the site, not about what is on any page of it. That has three consequences:

  • It can stop a whole site. It cannot hide one picture while leaving the rest of the page.
  • Images shown inside an app (a feed, a chat, a game) come from the app's own servers. If that app's address is not blocked, the DNS filter has nothing to act on, and it does not look at the pictures themselves.
  • A site that mixes ordinary and adult material is an all-or-nothing choice: a filter either blocks the name or it does not.

This is a property of the technique, not a flaw in any one product. For how DNS filtering works in more detail, see DNS to Block Porn: Free Family DNS on Android, Step by Step.

What does work on images

Several free tools act on images, each in one place.

SafeSearch on Google

Google's help page says SafeSearch "attempts to identify and filter inappropriate content" in Google Search, and lists three settings:

  • Filter: "Blocks all explicit results."
  • Blur: "Blurs explicit images. This is the default setting, if "Filter" doesn't apply." Google adds that it "helps blur explicit images, but explicit text and links can show if they're relevant for your search."
  • Off: "Shows all results, which may include explicit content."

The limit is stated on the same page: "SafeSearch only works on Google Search. It doesn't affect content on other search engines or websites." On a computer you open your SafeSearch settings and "Select Filter, Blur, or Off." Our SafeSearch guide has more: How to Turn On SafeSearch on Google, Bing and YouTube.

SafeSearch on Bing

Microsoft's page says "SafeSearch is a Bing setting that filters out inappropriate web content." On Bing.com you open Settings, choose More, then pick "Strict, Moderate, or Off" and Save. We did not find a Microsoft statement on that page about blurring, so we do not describe what each level does to images.

Apple: Sensitive Content Warning

Apple's page says: "Sensitive Content Warning warns you about photos or videos that might contain sensitive content before you view them, including nudity or gore and violence." If something is detected, "it's blurred before you view it." Apple lists where it works: on iPhone or iPad, Messages, AirDrop, Contact Posters, FaceTime calls and video messages, shared photo albums, and when you select a photo or video to share in some third-party apps. It requires iOS 17 or later; gore and violence detection requires iOS 27 or later.

To turn it on, in Settings select Privacy & Security, scroll down, select Sensitive Content Warning, and turn it on. Apple says it uses on-device machine learning and that Apple "doesn't receive an indication that sensitive content was detected." Note what is not on Apple's list: it is not described as filtering web pages in Safari.

For a child's device, Apple has a separate feature, Communication Safety, which "warns them, blurs the content, and provides helpful resources." It is set up for a child in a Family Sharing group through Screen Time. Our iPhone guide covers the wider picture for adults: How to Block Explicit Content on iPhone: Music, Books, Apps, Siri and Web.

Google Messages: sensitive content warnings

Google's page says the feature can "Detect and blur images or videos that may contain nudity in Google Messages," and that detection and blurring "happens on the device." For adults it is off by default. The path Google gives is to open Google Messages, tap your profile picture or initial, then Messages settings, scroll to "Protection & safety," tap Protection & safety, then Manage sensitive content warnings, and turn on Warnings in Google Messages. Google also says: "The sensitive content warnings feature isn't perfect. It may occasionally detect images or videos that don't contain nudity or not detect images or videos that contain nudity."

What about tools that take screenshots?

Some accountability tools work differently from blockers: instead of stopping a site by name, they capture or analyse what appears on screen and pass it to another person or service. We are not naming or describing any specific product here, because we only describe other companies from their own pages. If you are weighing one, read its own page for what it captures, where that goes, and who can see it.

The trade-offs are worth thinking through in advance. These are our observations, not findings from a study:

  • Privacy: a tool that looks at screen content is a different level of access from one that only matches site names. Ask who can see the captures and how long they are kept.
  • False flags: image classification is not exact. Google says its own warnings make mistakes in both directions, and a different tool will not be different in principle.
  • Purpose: a blocker stops a visit before it happens; a screenshot tool reports after. They answer different needs, and some people use both.

Putting it together

In our view, a realistic setup combines layers, each doing one job:

  1. A whole-site blocker so adult sites do not load in any browser or app.
  2. SafeSearch on Google (and Bing, if you use it) so explicit results are filtered or blurred.
  3. Sensitive content warnings in the messaging app you use, if you want unwanted images blurred before you see them.
  4. Support from people, which no setting replaces. To compare the kinds of blocker, see Porn Blockers Compared: DNS, Screen Time, Apps and Router Filters.

FAQ

Can a DNS porn blocker hide images on a page I can still open?

No. A DNS filter acts on the name of a site before the page loads. It does not look inside a page that is allowed to load.

Does SafeSearch blur images everywhere?

No. Google says it "only works on Google Search" and does not affect other search engines or websites. Clicking through to a site is outside its reach.

Does Apple's Sensitive Content Warning block porn sites?

Apple's page describes it as blurring photos and videos in the apps it lists, such as Messages and AirDrop. It does not describe it as a website blocker. For websites, see How to Block Explicit Content on iPhone: Music, Books, Apps, Siri and Web.

Can I change a filter on a phone or network I do not control?

If a parent, school or employer set it, it is theirs to change. Talk to them rather than looking for a way around it.

Where Mamori fits

Mamori blocks whole adult sites by name, across the whole phone, every browser and app. It filters DNS, the lookup an app makes to turn a site name into an address. It does not hide or blur individual images, on a page or inside an app. It also takes no screenshots and sends no reports to anyone.

On Android it checks each lookup on the phone against a blocklist stored on the device. On iPhone and iPad, lookups go over encrypted DNS to Mamori's filtering server so adult sites can be blocked, and it can also switch on Apple's own adult-website filter in Screen Time. It has a switch that forces SafeSearch on Google and Bing, and a lock you choose (a cooldown timer, a random phrase, or a PIN a trusted person can hold).

Honest limits: Android allows one VPN at a time, so another VPN or blocker can switch Mamori's filter off. On any phone, a VPN with its own DNS can get around a DNS filter. There are no accountability reports or partner alerts, and no blocker replaces support from people or a professional.

You can get Mamori from the App Store or Google Play on the homepage: mamoriblocker.com (7 days free on the monthly and annual plans, or a one-time lifetime option).

Related guides

How to Block JAV and Hentai SitesHow to block JAV and hentai sites: free SafeSearch, family DNS and Screen Time options, why list coverage matters, and how to add what slips through. Private Browsing, Incognito and Porn Blockers: What Gets Around WhatDoes private browsing or Incognito get around a porn blocker? What Apple and Google say, what their pages leave out, and a quick test for your own phone. 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.

Sources

Last checked 9 Nov 2026. This guide is general information, not medical advice.