How to block porn on a Mac
Blocking porn on a Mac is harder than on an iPhone, and it is worth knowing why before you start. On iPhone, every browser runs on the same engine, so one filter can cover all of them. On a Mac, each browser brings its own engine and its own settings, so there is no single switch that covers everything. Here is what actually works, including how to cover your Mac and your phone at the same time.
Option 1. Escape, the Safari blocker on your Mac
Escape blocks adult sites in Safari on your Mac for free, the same 11,868-site list it uses on your phone, plus any sites you add. The custom sites you block on your iPhone sync to your Mac over iCloud, so you set them once. If you go premium, one subscription covers your iPhone, iPad, and Mac through Apple's universal purchase, with no second purchase and no account. It lives in your menu bar and launches at login. More on Escape for Mac.
Option 2. macOS Screen Time, the bypass-resistant layer
Built into your Mac, the same as on iPhone. Open System Settings, then Screen Time, then Content and Privacy, then Content Restrictions, and limit adult websites. Unlike a plain content blocker, it resists Safari's "Reload Without Content Blockers" option, which is what makes it the bypass-resistant layer on a Mac. Escape gives you one-tap guidance to turn it on. Set a Screen Time passcode that you do not hold yourself, the same idea as on the phone, so turning it off is not a four-tap decision. The full walkthrough is in the bypass-resistance guide.
Option 3. Network or DNS filtering, for other browsers
Escape's Safari blocker and Screen Time both center on Safari. If you also use Chrome, Firefox, or another browser on your Mac, a network-level filter covers every app on the computer because it sits in front of all of them. It takes a little setup, and there are free and paid options. The trade-off is that it is one more thing to manage, and a savvy person can change network settings, so pair it with a passcode held by someone else if you can.
The honest part about computers
A Mac is a more open machine than a phone, which means a determined person has more ways around any one filter. That is not a reason to skip it. It is a reason to layer. Escape's Safari blocker handles everyday browsing, Screen Time adds the part that resists the reload trick, and a passcode you do not hold makes the whole thing harder to undo in a weak moment. The goal is the same everywhere. Make it inconvenient enough in the weak moment that the urge passes.
For the phone side of this, see the complete iPhone guide. For why blocking across every browser matters, see the all-browser guide.