Blocking a site in Chrome is easy. Keeping it blocked is the hard part. Most guides stop at "install an extension" and never mention that one keyboard shortcut, Cmd+Shift+N, gets around most of them. This guide covers four methods that work on a Mac today. For each one it shows the loophole and how to close it, and how easy the method is to undo on a bad day.
The four methods at a glance
| Method | Covers Incognito? | Covers other browsers? | How easy to undo | Needs admin? |
|---|---|---|---|---|
| Blocker extension | Only if you allow it | No | One toggle | No |
| Chrome policy (URLBlocklist) | Yes | No | Delete a profile or file | Yes |
| Screen Time | Varies by browser | Not reliably | Two clicks without a passcode | No |
| Hosts file | Yes | Yes | Edit one file | Yes |
| System-level blocker app | Yes, if it checks | Yes | Depends on its lock | Yes, at install |
No method is perfect. The right one depends on who you're blocking the site from. If it's a passing habit, an extension is fine. If it's you at 11pm with a deadline tomorrow, you need something that doesn't stop at Chrome.
Method 1: Use a blocker extension
An extension is the fastest route. It installs in seconds, needs no admin password and shows a block page instead of the site. Three popular options, with facts from their own Chrome Web Store listings:
- [LeechBlock NG](https://chromewebstore.google.com/detail/leechblock-ng/blaaajhemilngeeffpbfkdjjoefldkok) is free. It offers up to 30 block sets, time windows, daily time allowances, a lockdown mode, a delay countdown and password or random-code protection for its own options. It's the most flexible free choice.
- [StayFocusd](https://chrome.google.com/webstore/detail/stayfocusd/laankejkbhbdhmipfmgcngdelahlfoji) is built around a daily time allowance and a "nuclear option" that its listing says cannot be canceled. Reviewers have pointed out that turning the extension off defeats it.
- [BlockSite](https://blocksite.co/pricing) has a free tier and a Premium plan. Its pricing page showed a discount offer but no plan prices when we checked on 23 October 2026. It also has a Safari extension and phone apps.
Steps
- Open the extension's page in the Chrome Web Store and click Add to Chrome.
- Open the extension's options and add the sites you want blocked, for example youtube.com.
- Go to chrome://extensions, click Details on the extension and turn on Allow in Incognito.
- If the extension can protect its options with a password or delay, turn that on too.
Where extensions fall short
- The off switch is one click away. Any extension can be turned off or removed from chrome://extensions, and the "Allow in Incognito" switch can be turned off just as easily.
- It only covers Chrome. Open Safari, Firefox or Arc and the site loads.
- Guest mode and new profiles start clean. A guest window or a new Chrome profile has none of your extensions.
Method 2: Use Chrome's URLBlocklist policy
Chrome has a built-in website blocker that most people never see, because it's meant for IT departments. The URLBlocklist policy stops pages from loading and shows Chrome's own "blocked by your administrator" error. It works in Incognito too, because the browser enforces it, not an extension. Google's admin guide covers the details, but nothing stops you using it on your own Mac.
How Chrome on a Mac reads policies
On macOS, Chrome reads policies from managed preferences in the com.google.Chrome domain. The normal way to set them is a configuration profile (a .mobileconfig file) that you install in System Settings. MDM tools such as Jamf or Applivery create the same thing. A plain `defaults write com.google.Chrome` in Terminal is not enough. Chromium's source treats that as a "recommended" setting rather than a mandatory policy, so don't rely on it.
Steps
- Create a configuration profile with a payload for the com.google.Chrome domain. Many free profile editors can do this, as can an MDM if you already use one.
- Add a URLBlocklist array with one entry per site, for example `youtube.com` and `reddit.com`.
- Optionally add URLAllowlist entries for exceptions, such as one course page on a blocked site. The allowlist wins over the blocklist.
- Install the profile in System Settings > General > Device Management (you'll need an admin password).
- Quit and reopen Chrome, then go to chrome://policy to check the policy shows up and has no errors.
The URL format, briefly
- `example.com` blocks the site and all its subdomains, so `m.example.com` is blocked too.
- `.example.com` (with a leading dot) blocks only that exact host.
- A trailing wildcard such as `https://example.com/*` isn't allowed. Write the path without it.
- Each list holds up to 1,000 entries, and the most specific match wins (Google's URL format guide).
- Never block `chrome://settings`, or you lock yourself out of Chrome's settings.
Close the other Chrome loopholes
URLBlocklist already covers Incognito. These extra policies, from Chromium's own policy definitions, close the remaining doors inside Chrome:
- IncognitoModeAvailability = 1 turns Incognito off entirely. Useful if you rely on an extension instead of URLBlocklist.
- BrowserGuestModeEnabled = false removes guest windows.
- BrowserAddPersonEnabled = false stops new Chrome profiles being created.
- DeveloperToolsAvailability = 2 turns off DevTools, which some people use to get around page-level blockers.
You can also force-install a blocker extension with ExtensionInstallForcelist, so it can't be removed from chrome://extensions. One catch: Chromium's own policy notes say force-install doesn't apply to Incognito. Pair it with IncognitoModeAvailability = 1, or the extension still won't run there.
Where Chrome policies fall short
- Only Chrome obeys them. Safari, Firefox and Arc don't read Chrome's policies. Brave, Edge, Vivaldi and Opera read their own policy domains, not com.google.Chrome.
- Undoing it is quick if you're an admin. Removing the profile in System Settings takes a few clicks and your password.
- Changing the list is slow. Every edit means a new profile and a Chrome restart, so it suits a fixed list, not daily changes.
Method 3: Use Screen Time
Screen Time is built into macOS, so there's nothing to install. In current macOS the setting is under System Settings > Screen Time > Content & Privacy > App Store, Media, Web, & Games. There are three choices: Unrestricted Access, Limit Adult Websites and Allowed Websites Only. To block particular sites, choose Limit Adult Websites, click Customize and add them to the Restricted list. We walk through every click in our guide to blocking websites on Mac.
Does Screen Time work in Chrome?
Sometimes, and that's the honest answer. Some guides state that Screen Time blocks at the DNS level in every browser. Apple's own Mac guide lists these web limits under a Safari heading and doesn't say they cover other browsers. iMore found that Limit Adult Websites didn't filter reliably in third-party browsers, while Allowed Websites Only did. That report may describe an older macOS, so test it yourself. Add a site, then open it in Chrome, in an Incognito window and in any other browser you use.
Where Screen Time falls short
- It's easy to switch off. Without a Screen Time passcode, removing a site takes two clicks. Setting a passcode helps most when someone else keeps it.
- There's no "block only these sites" mode. You get the restricted list through Limit Adult Websites, which also changes what else is filtered.
Method 4: Block below the browser
Every method so far either lives inside Chrome or depends on how Chrome behaves. The way to close the "just open another browser" loophole is to block at the level of the whole Mac.
The hosts file is the free version. Adding a site to /etc/hosts points it nowhere, in every browser. It needs Terminal and an admin password, gives you a connection error rather than a block page, and is just as easy to remove. The full steps are in our Mac blocking guide.
A system-level blocker app does the same job with a schedule, a block page and a lock. Options include FocusDragon, SelfControl, Cold Turkey and Freedom. Our roundup of the best website blockers for Mac compares them. If you want something free and timer-only, SelfControl is a good pick.
How FocusDragon handles Chrome
FocusDragon uses the same Chrome mechanisms described above, set up for you:
- An extension with a real block page. Blocked sites show a FocusDragon "Site Blocked" page, and blocking a domain covers its subdomains. The same extension works in Chrome, Edge, Brave, Opera, Vivaldi and Comet. Firefox and Safari have their own.
- ExtensionInstallForcelist, done for you. FocusDragon's background service adds the Chrome policy that marks the extension as managed, so it can't be removed from chrome://extensions during a block. Since version 2.0.15 it removes that policy again when you uninstall the app.
- Incognito is checked, not assumed. While a website block is running, a browser without the extension, all-site access and private-browsing access is closed. Reopening it doesn't help, because the check runs again every time.
- Other browsers count too. Supported browsers without the extension, and unsupported browsers, are force-quit during blocks. Each browser names the switch differently: Allow in Incognito in Chrome, Run in Private Windows in Firefox, Allow in Private Browsing in Safari.
The core blocker is free. Pro ($19.99 once, as of 23 October 2026) adds locked blocks and bypass prevention. That's the tamper-resistant mode for people who undo their own blocks. See pricing for the current split.
When FocusDragon isn't the right fit: if you need the same blocklist on your phone, Freedom covers both. If you only want a light nudge, LeechBlock NG with Incognito allowed is free and may be all you need. And FocusDragon's Mac app needs macOS 14 or later.
Which method should you use?
- You just want fewer accidental visits: a free extension like LeechBlock NG, with Allow in Incognito turned on.
- You manage a family or shared Mac: Chrome's URLBlocklist policy plus the Incognito, guest and profile policies, and Screen Time with a passcode someone else holds.
- You keep undoing your own blocks: a system-level blocker with a lock that covers every browser. See our guide to website blockers for Mac.
- The distraction isn't one site: for searches and feeds you can't predict, AI Focus judges what's on screen against your goal instead of a fixed list.
Whatever you choose, test it the way you'd try to beat it. Open the site in Chrome, then in an Incognito window, then in a guest window, then in Safari. If it loads anywhere, that's where you'll end up on a hard day.