Firefox for iPhone Now Has a Built-In Ad Blocker. Here Is What It Actually Blocks

Key points

• Mozilla is rolling out an optional ad blocker inside Firefox for iOS in 2024, switched off by default.
• The blocker uses EasyList, a widely used filter catalogue, to stop ads from loading before they reach your screen.
• It does not block ads inside Google or Bing search results, nor sponsored tiles on the Firefox home screen.
• A separate report from Adblock Plus warns that advertising embedded inside AI chatbots is coming, and will be far harder for any filter to catch.
• Firefox is not the first iOS browser to offer ad blocking; Brave has included it for years.

Firefox on iPhone is getting a built-in ad blocker. Mozilla, the non-profit organisation behind the browser, confirmed the feature is arriving through a staged rollout, meaning it may not have appeared in your app yet. Patience required.

The blocker is off by default. To turn it on, you tap a single toggle inside the app settings. That simplicity is genuinely useful, because most third-party ad blockers on iOS require separate installation and configuration.

What does it actually block?

The blocker stops quite a lot, but not everything. It covers ads from third-party advertising networks, tracking scripts tied to those ads, ads placed directly by websites, and pop-ups or overlay banners.

What it does not touch: ads inside Google and Bing search results, and sponsored content tiles on the Firefox home screen or new-tab page. Mozilla also acknowledges in its FAQ that some websites serve ads in ways the current filter list simply does not recognise.

The filter list is based on EasyList, an open catalogue maintained by volunteers that has been a backbone of ad blocking for well over a decade. It is solid, but not exhaustive.

For users who want stronger coverage, dedicated apps such as Wipr or Ghostery, which act as content blockers that other browsers can also use, will still catch more. Brave, a privacy-focused browser that has offered ad blocking on iOS for years, also goes further.

The decision to leave Google and Bing search ads untouched is worth noting. Mozilla receives a significant portion of its annual revenue from Google through a deal that makes Google the default search engine in Firefox. The company has not offered a technical explanation for the omission, only confirming it in its FAQ.

What is the bigger picture?

Ad blocking on mobile browsers is already a contested space. The more consequential threat, though, may come from a different direction.

Adblock Plus published a report on the same day Mozilla's feature gained attention, warning that advertising inside AI chatbots, the conversational software tools that answer questions in plain text, is likely coming soon. Those ads, the company said, could be generated on the fly and woven into responses in ways that look nothing like a banner or a pop-up. Standard filter lists would struggle to catch them.

For ordinary users, the practical upshot is simple. Firefox's new toggle is a worthwhile convenience if you already use Firefox on iPhone and want fewer ads with zero setup. It is not a complete solution, and the gaps around search ads may frustrate users who expected full coverage.

If you want stronger blocking today, a dedicated content blocker installed alongside your browser of choice still gives you more control. That may become even more relevant as advertising shifts into territory that filters were never designed to handle.

Common questions

Do I need to download anything extra to get this?

No. The blocker is built into the Firefox app for iOS. When the update reaches you, a toggle appears in the app's settings, and switching it on is all you need to do.

Will it work on Android or desktop Firefox too?

Not as part of this rollout. This feature is specific to Firefox for iOS; desktop Firefox already supports a wide range of third-party ad-blocking extensions, which generally offer more granular control.