How to Block Websites on Mac (Free ADHD App)

TL;DR: To block websites on a Mac, use Screen Time for Safari only, the hosts file for every browser, or Download for Mac — Focuh is a free ADHD Mac app that blocks sites system-wide and includes a Today / week / goals / loops todo list. Mac and the web app use a free Clerk account. The Chrome extension is separate and is not this product.

A blocked website keeps coming back on a Mac when the block only covered one browser. You turned it off in Safari, then opened Chrome. Below are the real steps for each free method, then Focuh as the Mac app that also plans the work you meant to do.

How do I block websites on Mac for free?

You do not need a paid blocker.

1. Screen Time — built in, two minutes, Safari only. Steps below.
2. Hosts file — built in, covers Safari, Chrome, Firefox, and Arc. Easy to undo.
3. Focuh — Download for Mac. Free app. Blocks every browser during a focus session, then you work from Today (or launch the web app with the same Clerk account).

Pick the lightest one that will actually hold. If you already know you will switch browsers, skip Screen Time.

How do I block websites on Mac using Screen Time?

Screen Time is the built-in filter. It is free and it only governs Safari.

1. Open System Settings → Screen Time.
2. Click Content & Privacy and turn on Content & Privacy Restrictions.
3. Go to Content Restrictions → Access to Web Content and choose Limit Adult Websites.
4. Click Customize. Under Restricted, add the full address — for example https://www.reddit.com.
5. Set a Screen Time passcode (separate from your login password) so the restriction is not a two-click undo.

Safari will refuse the site. Chrome, Firefox, and Arc will not. And it is your passcode, so you can lift it the moment the urge is strongest — which is when you should not be able to.

How do I block websites on Mac across every browser?

Edit the hosts file. It sits below the browser, so the domain fails in Safari, Chrome, Firefox, and Arc at once.

1. Open Terminal.
2. Back up the file: sudo cp /etc/hosts /etc/hosts.backup
3. Edit it: sudo nano /etc/hosts
4. Add a line for each hostname (include www and mobile if they exist):

127.0.0.1 reddit.com
127.0.0.1 www.reddit.com
127.0.0.1 m.reddit.com

5. Save with Control+O, exit with Control+X.
6. Flush DNS: sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder

The site is blocked until you delete those lines. That takes about thirty seconds, so this is a baseline, not a session you cannot talk yourself out of. There is no timer and no Today list.

Does Screen Time block Chrome on Mac?

No. Screen Time's website limits do not follow you into Chrome, Arc, or Firefox. That is why a Safari-only block feels like it "stopped working" twenty minutes later: you opened another browser.

A browser extension has the same ceiling — it blocks one browser. It is a fair tool if you never leave that browser. It is the wrong tool if the habit is "hit a wall, open the same site somewhere else."

What is the best free Mac app to block websites?

If you want the block tied to work time — on, then off — and you want a todo list next to it, download Focuh for Mac.

Focuh is a free macOS app. During a focus session it blocks your list of sites at the operating-system level (Accessibility APIs), so the site is unreachable in Safari, Chrome, Firefox, and Arc at the same time. It is harder to switch off mid-session than Screen Time.

It is also the todo-list product: Today, week, goals, and loops. Blocking without a next task is how a session turns into staring at the desktop. The Mac app and the web app Today view share a free Clerk account so the same list is on both.

Honest limits:

• Mac and web need that Clerk account. That is how Today and the week stay in sync. The Chrome extension can run without an account — that is extension-only, and it is not the product this guide is for.
• You grant Accessibility once. That is what lets the block cover every browser.
• No fake install counts here. Try it on your machine.

Setup

1. Download for Mac and install the app.
2. Sign in with a free Clerk account (same account as the web app).
3. Add the sites you actually open on autopilot.
4. Grant Accessibility when macOS asks.
5. Start a focus session. Put one task on Today. If you would rather plan in the browser, launch the web app.

SelfControl is the other strong free Mac option if you only want a timer you cannot cancel and you do not need a planner. Screen Time remains the right choice when you only use Safari and you trust yourself with the passcode.

Which method should I use to block websites on Mac?

Method	Free?	Every browser?	Session / timer?	Planner (Today / week / goals / loops)
Screen Time	Yes	No (Safari only)	No	No
Hosts file	Yes	Yes	No	No
SelfControl	Yes	Yes	Yes	No
Focuh Mac app	Yes	Yes (OS-level)	Yes	Yes

Safari only, and you trust yourself — Screen Time.

Every browser, no app — hosts file.

You keep going back — Download for Mac. Start a session, work from Today. Same account: Launch web app.

For a Safari-only walkthrough see how to block websites on Safari. For skipping Screen Time entirely see how to block websites on Mac without Screen Time.