Safari Ad Blocker: How Content Blockers Work on a Mac
Nemo · · 4 min read
Safari doesn’t block ads on its own. To block them you install a content blocker, a Safari extension from the Mac App Store, and turn it on in Safari › Settings › Extensions. Safari then checks every request a page makes against the blocker’s rules and drops the ones that match, before they load. Safari’s own privacy settings add tracker protection on top. If you’d rather not install anything, a WebKit browser such as Monok ships the same kind of blocking built in.
Why does Safari need an ad blocker at all?
Ads cost more than screen space. A page with ad scripts loads extra code, makes dozens of extra requests, and keeps running scripts after it has drawn. On a laptop that shows up as a slower page, a warmer Mac and a fan you didn’t hear before you opened the tab. Trackers are quieter but do the same kind of work: they report what you read to companies you never chose to visit.
Safari’s built-in protection limits what trackers can learn. It does not stop the requests from being made.
How does a Safari content blocker work?
Apple’s design is different from extensions in other browsers. A content blocker never sees the pages you visit. It hands Safari a list of rules (“block requests to this domain”, “hide elements with this class”), Safari compiles them, and WebKit applies them itself. The extension can’t read your browsing, which is why Apple built it that way.
| Step | What happens |
|---|---|
| Install | Get a content blocker app from the Mac App Store and open it once |
| Turn it on | Safari › Settings › Extensions, tick the blocker |
| Rules load | The app gives Safari its filter lists as content rules |
| Browsing | WebKit checks each request and element against the rules and blocks matches |
| Exceptions | Most blockers let you allow a site from the toolbar or their app |
Many blockers are built on the same public filter lists: EasyList for ads and EasyPrivacy for trackers. The lists are what decide what gets blocked; the app mostly decides which lists to load and how often to update them.
Which Safari settings help without an extension?
Turn these on first. They cost nothing and need no install:
- Prevent cross-site tracking: Safari › Settings › Privacy. On by default; check it.
- Hide IP address: in the same pane, hide your IP address from trackers.
- Reader: Shift+Cmd+R shows an article without most of the page around it.
- Website settings: Safari › Settings › Websites lets you deny notifications, camera and pop-up windows per site.
None of these remove ads. They limit tracking and cut noise.
Is there a browser with the blocker built in?
Yes. Monok is a small Mac browser that renders pages with the same WebKit as Safari, and it compiles EasyList and EasyPrivacy into WebKit’s own content blocker out of the box. That is the mechanism a Safari content blocker uses, with nothing to install. Blocked requests never leave the Mac, so pages get lighter. The deep dive on network-level blocking explains why that matters for speed.
What you get in version 0.1.0:
- Blocking on by default, with the lists updated weekly.
- The ⋮ menu shows how many requests were blocked on the page and turns blocking off for one site.
- Settings turns blocking off everywhere if you ever need it.
It is not a Safari replacement in every way yet: there are no extensions, no sync between Macs, and it is an early preview. What it does add is a Magic Bar instead of an address bar, tabs that split into panes, and a terminal in a pane next to the page. The home page has the tour.
What should you pick?
- You live in Safari and want fewer ads: install a content blocker that uses EasyList and EasyPrivacy, then turn on the privacy settings above.
- You want blocking without managing extensions: try a browser with it built in, like Monok.
- You care about memory: blocking helps, but the tabs you keep open matter more. The lightweight browser guide shows how to measure it in Activity Monitor.
If you keep a terminal open all day, the tmux cheat sheet is a good next read: the same split-pane habits work inside Monok.
Try it: download Monok for Mac, free while in preview, macOS 14 or later.
FAQ
Does Safari have a built-in ad blocker?
No. Safari blocks cross-site tracking and can hide your IP address from trackers, but blocking ads needs a content blocker extension, or a browser with blocking built in.
Can a Safari content blocker see my browsing history?
No. A content blocker only gives Safari a list of rules; WebKit applies them. The extension never receives the pages you visit.
Does an ad blocker make Safari faster?
Usually pages load less: fewer scripts, fewer requests. How much depends on the site.
Can I turn blocking off for one site?
In most Safari blockers, yes, from the toolbar or the app. In Monok, the ⋮ menu turns it off for the site you’re on.
Where do I get Monok?
On the download page. It is free while in preview and runs on macOS 14 or later.