Your ad blocker might be watching you. Yes, the extension you installed to keep trackers at bay might be tracking you. Wild, right?
We are living in a surveillance economy. Your data is worth a lot of money to the right buyer. So while ad blockers are supposed to help prevent unauthorized data collection, some predatory companies are using that general perception and trust to exploit you. These “fake” ad-blocker apps and extensions are quietly asking for full access to everything you do online. Not because they have to, but because they can.
It’s a real privacy blind spot that a lot of people overlook. In this piece, we’ll unpack the hidden risks behind ad blockers that overreach, explain what to watch out for, and show you how to stay protected without giving up the perks of a clean, ad-free internet. Let’s get into it.
Can an ad blocker collect user data?
Yes. An ad blocker can and often does collect user data to improve its services. However, it also has the opportunity to exploit it.
When you install an ad blocker, whether it’s a browser extension or a mobile app, you’re giving it full access to everything you do online. It sees the websites you visit, the content you load, and sometimes even what you type. That’s not shady on its own. Ad blockers need this access to strip out ads and trackers in real time. However, it does mean they hold a significant amount of power. And with great power comes… potential privacy problems.
Some ad blockers use that access responsibly. They work locally, don’t log anything, and proudly declare that they don’t track users. That’s what you want.
But there are others who abuse the trust. There have been real cases of ad blockers (or convincing fakes) that logged browsing data, monitored user behavior, or injected their own trackers. Some even joined affiliate programs or sold anonymized data to analytics firms. Sensor Tower, an analytics firm, was accused of using its ad blockers and VPNs to collect user data. Their products had over 35 million cumulative downloads across platforms.
So yes, ad blockers can collect user data. Whether they do comes down to the intent behind the code. And unless it’s open source or independently audited, you’re taking their word for it.
Why would an ad blocker want to collect data?
Money. As I said before, we live in a surveillance economy.
Building a good ad blocker takes time and effort. Maintaining filter lists, updating for browser changes, and responding to new ad techniques. If the blocker is “free,” then the question becomes: how is it paying the bills?
Some rely on donations, paid upgrades, or ethical partnerships. For others? Data is the currency. Here’s why a shady ad blocker might want to collect user data:
- Sell anonymized data: browsing habits to advertisers, data brokers, or research firms.
- Build behavioral profiles: what sites you visit, how long you stay, what you click.
- Whitelisting deals: let certain ads through and get paid for it (yep, that’s a thing).
- Affiliate tracking: sneak in code to earn a cut when you buy something online.
- Market intelligence: like Sensor Tower did. Secretly owning ad blockers to monitor which apps and sites are trending.
It’s the ultimate bait-and-switch. You install an ad blocker to stop tracking… and get tracked by the thing that was supposed to help you.
To sum up, if they don’t tell you how they make money, be wary. And if the privacy policy is unclear, dodgy, or non-existent? That’s a big red flag.
What are the safest ad blockers?
Not all ad blockers are created equal. Some just remove banners. Others go deeper and block trackers, malware domains, autoplay videos, and even cookie pop-ups. But if privacy is your top priority, here’s who deserves your trust.
1. Surfshark CleanWeb — all-in-one protection
If you’re already using (or considering) a VPN, Surfshark CleanWeb is one of the best ad blockers built into a security suite. It runs at the DNS level, so it filters out ads, trackers, and phishing domains before they even hit your browser.
- Blocks ads across browsers and apps
- Works on all devices (thanks to the VPN)
- Includes malware and phishing protection
- No browser extension required
2. AdGuard — most versatile standalone blocker
AdGuard is one of the most feature-rich and transparent ad blockers out there. It’s a browser extension, a mobile app, or a full desktop program that can block ads system-wide. And it’s run by a privacy-obsessed team that publishes regular transparency reports.
- Open-source filters, customizable blocking
- Works on Windows, macOS, Android, iOS, browsers
- Blocks video ads, in-app ads, trackers, crypto-miners
- Premium plan includes DNS-level filtering and parental controls
3. NordVPN Threat Protection — privacy bundle with ad/tracker blocking
NordVPN Threat Protection scans downloads, blocks trackers, and filters dangerous domains, all while tied into your VPN connection. It’s like Surfshark CleanWeb, but slightly more focused on malware protection.
- Runs in the background
- Blocks the tracker system-wide
- Integrated with NordVPN (no browser needed)
- Great for people who want lightweight privacy automation
4. Total Adblock — best “user-friendly” premium blocker
Total Adblock is flashy, polished, and designed for non-technical people who want something that just works. It’s from the creators of TotalAV antivirus and has a clean UI and solid ad-blocking.
- Blocks YouTube ads, banners, pop-ups, trackers
- Built-in malware protection
- Optional antivirus bundle
5. uBlock Origin — open-source, no-BS choice
If you want total control and no data shenanigans, uBlock Origin is the way to go. It’s open-source, super fast, and loved by privacy geeks for a reason.
- 100% free, forever
- No data collection of any kind
- Advanced filtering and custom rules
- One developer and a community of enthusiasts
Safest Ad Blockers (Ranked)
| Rank | Name | Why It’s Safe & Worth It | Monetization |
| 1 | Surfshark CleanWeb | DNS-level blocking + VPN + no tracking | Subscription |
| 2 | AdGuard | Customizable, trusted, open filters | Freemium |
| 3 | NordVPN Threat Protection | Lightweight privacy shield tied to VPN | Subscription |
| 4 | Total Adblock | User-friendly, polished, premium bundle | Subscription |
| 5 | uBlock Origin | Best-in-class privacy, totally free | Donations only |
Why do ad blockers need access to “all my data” on websites?
That permission pop-up isn’t lying. Most ad blockers do ask for access to “read and change all your data on the websites you visit.” And yes, it sounds ridiculous. Why does something built to block ads need to track my entire browser history? But the honest reason is that’s how ad blockers work.
To block ads, the extension needs to scan every page you load, in real time. It looks at which scripts are running, what content is loading, and whether anything smells like a tracker. Then it surgically removes those elements before the page fully renders. It’s a little like having a bouncer standing at the door of every website you open, tossing out the shady stuff before you walk in.
That level of control means the ad blocker needs broad access, not because it’s spying, but because it has to see the page to clean it up. No “limited access” mode would let it block ads and keep its hands completely tied. Browsers don’t offer that kind of nuance yet.
Can ad blocker extensions see sensitive information like passwords?
Technically, yes. If a browser extension can read and modify everything on a page, it could see anything you type, including passwords.
That doesn’t mean every ad blocker is snooping on your login forms. The good ones don’t touch password fields, cookies, or anything remotely sensitive. But the scary part is that they totally could.
Security researchers have flagged extensions (some of them pretending to be ad blockers) that quietly harvested login credentials, credit card details, and even authentication tokens.
Worse? Ad blockers often get acquired by different companies since they don’t make a lot of money. And that’s how previously good and trustworthy ad blockers can become surveillance tools. They push quiet updates that turned the blocker into spyware overnight, and users don’t even realize it.
So here’s the takeaway: If an extension’s model is shady and asks for access to all sites… think again.
How do free ad blockers make money without selling anything?
If an ad blocker isn’t costing you even a penny, how on earth are they staying afloat? Servers cost money, after all, and so does development, support, and keeping those filter lists up to date. And yet, many ad blockers claim to be “free forever” with no strings attached.
But, behind the scenes, the honest ones are finding ways to stay in business:
1. Acceptable Ads programmes
Some ad blockers, like Adblock Plus, will let non-intrusive ads slip through by default. These ads get a free pass if they meet certain criteria (no tracking, no auto-play, no annoying flash stuff). Companies can pay to get their ads on the whitelist, and you can just opt out if you’re not keen.
2. Freemium upgrades
Think of it like free core features, with optional extras available for a fee. AdGuard and other blockers will perform a basic job of blocking ads in your browser for free, but charge for device-wide blocking, additional privacy features, or custom DNS filtering.
3. Donations
Some projects, like uBlock Origin, are passionate about their work, run on open-source principles, and just rely on whatever donations they can get. No upselling, no gimmicks, just a commitment to doing the right thing and a slim operation that turns over as little cash as possible.
4. Affiliate deals
Some blockers will earn a small amount of money if you click a link to buy something, such as a VPN or security product. You’re not paying any more than you normally would, but the blocker gets a tiny kickback.
Free ad blockers aren’t always as dodgy as they sound. But it does mean you need to keep an eye on how that “free” is being funded.
Are free ad blockers selling my browsing data?
Some definitely do. Not all, but enough to be a worry
There’s been cases where free ad blockers, or apps pretending to be them, not only collected browsing data, but also sold it on to data brokers, advertisers,cor “research partners”. They promise to block ads, but then turn right around and flog your habits to the highest bidder.
Here’s how it usually works:
- The app quietly logs all the sites you visit without you ever noticing.
- Then it bundles that data up (sometimes masked, sometimes not).
- And finally, it sells it to firms that want to know what people like you are browsing.
It doesn’t always hide in plain sight by saying “we’re selling your data” in the privacy policy – often it’s hidden behind more innocuous language like “usage analytics” or “shared with partners to improve the service”. That’s the standard get-out clause.
Take the Sensor Tower example. They ran loads of dodgy mobile ad-blocker and VPN apps that secretly scooped up data and sent it back to a market research platform. Apple and Google eventually shut them down, but by then, millions of people had downloaded the dodgy apps.
So while not every free ad blocker is a data sell-out, the risk is there, and it often comes down to this simple rule: If you’re not paying cash, just make sure you’re not paying with your data too. Take a close look at the privacy policy. Look for open-source. Trust signals are important too. Because free can be a gift, or it can be a disguise
Does Manifest V3 stop ad blockers from collecting data?
Nope. Manifest V3 (MV3) isn’t designed to block data collection; it’s designed to change how browser extensions work, especially around performance, security, and content filtering.
In fact, some privacy advocates argue that MV3 makes it harder for advanced ad blockers to protect your privacy, not easier.
So what is Manifest V3, exactly?
It’s Google’s new extension framework for Chrome. Think of it as a rulebook update. A big one. MV3 introduces several restrictions to improve browser performance and reduce abuse by shady extensions. One of the biggest changes?
MV3 limits how extensions can intercept and block network requests.
Under the old system (Manifest V2), blockers like uBlock Origin utilized a powerful API (webRequest) that provided them with deep, real-time control over every request made by your browser. MV3 replaces that with a tamer API (declarativeNetRequest) that uses pre-set rules. It’s faster, more secure… but also less flexible.
Okay, but does that mean extensions can’t harvest data anymore?
Unfortunately, no.
Even under MV3, extensions can:
- Request broad permissions (like access to all sites).
- See the URLs you visit.
- Log browsing activity (if coded to do so).
- Phone home data to their servers.
There’s nothing in MV3 that prevents a developer from collecting user data, unless the extension store enforces tighter policies. Which doesn’t always happen fast enough.
Does MV3 help or hurt privacy?
It’s complicated. MV3 was pitched as a security win, and in some ways, it is. It limits certain kinds of abuse by extension. However, privacy advocates argue that it hobbles the best, most private ad blockers (like uBlock Origin), while doing nothing to stop malicious ones that were already harvesting data under the radar.
Wrapping Up — Should You Trust Your Ad Blocker?
Yes. If it’s one of the good ones. Just make sure to check the user reviews from time to time.
Ad blockers are still one of the best tools to help reclaim control over your browsing. They cut through all the junk and make the web actually a more bearable place. But because of the way they work, you can’t just install the first one you come across without doing your research.
The thing is, the same access that lets a blocker clean up your online experience also means it gets to see everything you do online. And that’s a whole lot of power. Not every tool deserves that kind of access.
So don’t just grab the first ad blocker that promises the world for free. Take a closer look at their business model. Do they actually sell your online behaviour? And if you’re not sure – go with the blocker that’s got the least to gain from watching you.
Clean pages are a good start, but clean privacy practices are even better.