You've probably heard of adblockers.
You've probably also heard of tracker/privacy blockers.
Lastly, you've probably wondered if there was a difference between the two.
The short answer is: yes, there is.
Let me explain further...
Of course, as you already know, what adblockers do is right in the name:
Adblockers are technologies that block advertisements on webpages.
Not every blocker is a browser plugin - some can be applications or standalone programs that block ads across an entire device, even outside of a specific browser.
More than likely though, you're probably the most familiar with browser plugins that serve as adblockers. Popular (and not so privacy friendly) plugins include Ghostery and Adblock Plus.
Adblockers can also function on a network-wide level. For example, if you happen to blacklist (block) a known ad URL via your router, then you'll be blocking ads served from that specific domain across your entire home network.
However, not all adblockers use the same process/methods to block the ads you see. Since adblockers come in many different forms, how ads are blocked/filtered can occur in many different ways:
- Domain blocking
- Specific URLs (as explained in the home router example above)
- Blocking lists (can be defined by the user)
- Ad display type (video ads vs banner ads)
- Ad size
This isn't a comprehensive list of the different ways adblockers block ads. You can view
more information on adblocking methods on Wikipedia.
If adblockers block ads, then what do tracker/privacy blockers do?
Well, the super short answer is that they block more than just ads.
Tracker/Privacy blockers (often lumped together) often block tracking scripts, third-party requests, invasive first and third-party analytics, and other cross-site tracking technologies. They're focused on protecting user privacy, as opposed to just getting rid of unsightly ads.
And often times, in blocking various tracking methods, they often block ads as well. This collateral happens because online advertisements often utilize tracking methods when viewed/served and clicked.
Like adblockers, privacy blockers can come in many different packages. Privacy blockers can be deployed as browser plugins, standalone applications or programs, and via DNS filtering.
Also like adblockers, different privacy blockers use varying methodologies for blocking invasive ads and/or tracking technology:
- Using filtering lists of known tracking domains (example: EasyList)
- Deploying algorithms that learn what sites track you
- Quantifying rules (how many times have requests been sent to third-party sites?)
Explore different tracker blocking avenues
on our dedicated tracker blocking page.
|Blocks ad tracking
|Blocks site analytics
(ex: Google Analytics)
|only if ad-related
|| (if supported)
|| (if supported)
While adblockers can certainly be useful because they block many unsightly, sometimes unsafe, and sometimes privacy-invading ads, they're often limited to just that one function.
Additionally, many dedicated adblockers have been found to be "double-agents":
- Adblockers sometimes will whitelist ads if the advertiser pays enough, such as the case with the popular AdBlock Plus. This results in ads "slipping through" even with the adblocker enabled.
- Adblockers can engage in data collection of users, such as the case with Ghostery. Data collected can include browsing history and identifiable information, which is often sold to data brokers and ad networks.
If you're trying to improve your privacy online, regardless of your personal threat model, you should opt for a trusted privacy/tracker blocker instead.
This is because privacy blockers do more than just block ads - they will also block invasive site analytics and tracking scripts.
Trusted privacy blockers can include browser plugins such as uBlock Origin or DNS filtering software such as PiHole.
That wraps this post up; as always, stay safe out there!