But that still leaves my devices largely open to ads when I’m not on my home network, as well as the various apps that I use that are chock full of ads — including web browsers that aren’t Safari.
As you can imagine, I was keen to give Filtr a spin. Filtr particularly appealed because, as Calderolla states in her privacy policy, her apps “do not collect personal data.” Her apps also don’t need to access any personal information to work, and neither does Apple’s URL filter feature.
For me, it was a no-brainer — all upside, and no tradeoff. I paid for the $5 annual subscription, added the URL filter to my iPhone, and that was that. The relief was immediate. Every app I opened loaded without its usual flood of ads. Some ad slots showed greyed placeholder spaces where the ads would have loaded.
Calderolla told me this week that Filtr is the first app so far to utilize the URL filters feature; though, that may be in part because it was a “nightmare” to get it to work, some of which she described in a May blog post. Calderolla said that Apple’s documentation on the URL feature was sparse, requiring her to do much of the work to understand how to implement and use the feature.
The URL filter feature relies on an advertising blocklist that Calderolla maintains. Calderolla explained that Filtr consults a “pre-filter” blocklist that is stored on the user’s device and is kept constantly up-to-date via automatic updates in the Wipr app. The pre-filter list determines if a website is not on the block list and, most of the time, the website loads as normal. But if the pre-filter list finds that a website might be on the block list, it will quickly confirm against the list on Calderolla’s servers. Calderolla said that these requests are routed through Apple’s servers as a proxy so that app developers do not know who is querying their blocklists.
This means that you can set up Filtr once and generally never have to think about it again. (For a security or privacy product, that’s high praise.)
There are some caveats, but far from dealbreakers. No ad blocker is perfect, period, but minimizing exposure to the ad networks as much as possible is a major win for your privacy. Filtr also does not block ads that are served from the same network as the website you’re visiting. That means you will still see ads in the Facebook, Google, and Reddit apps, as well as any other app that serves ads from its own domain, as blocking these would block the domain entirely, rendering it likely very broken. (Lifehacker also tested and reviewed Filtr and found that using their mobile websites instead of their apps will still allow Wipr to block the ads.)
Wipr is a universal app that costs $5 in the Apple App Store and works across all of your Apple devices. Filtr costs an additional $5 each year, or $25 for a one-time lifetime payment, via in-app purchase.
