How to Block and Unblock Websites on Mac

Open the Terminal application. Open Applications > Utilities > Terminal. The application allows you to edit the hosts file – providing the IP address of a specific URL. By combining with the fake IP address of a particular URL, you can prevent the browser from accessing that website.

• This method is not 100% guaranteed and is not too difficult to overcome. But this is a quick way to get a website on a personal computer so as not to affect work productivity. While this is not the only way to block user access, you can combine it with other methods for greater effectiveness.

Backup the hosts file. If you make a mistake when editing the hosts file, all internet access may be blocked. Making a copy of the hosts file allows you to reuse the original if this is the case. With just one simple command: ^[2]

• In Terminal, enter the command sudo /bin/cp /etc/hosts /etc/hosts-original exactly as it appears.
• Press the Enter button on the keyboard to execute the command.

Enter the administrator password. Terminal will ask you to enter your password. Type the password and press Enter . The mouse pointer will not change position when you enter the password.

Open the hosts file. Type the command below and press Enter : sudo /Applications/TextEdit.app/Contents/MacOS/TextEdit /etc/hosts . This command will open your Mac’s hosts file in TextEdit mode in Terminal. ^[3]

• Alternatively, you can edit the hosts file in the Terminal window with the command sudo nano -e /etc/hosts .

Ignore existing text. The hosts file has several IP addresses associated with “localhosts”. Do not edit or delete this text or the browser will not work. Hover over the new line at the end of the text.

• If you use the Terminal main window, use the arrow keys to move down to the last line of the page.
• Some users have reported an error, you can only add newlines above the existing text in the hosts file. ^[4]

Type 127.0.0.1 . This is the internal IP address. If the web browser goes directly to this address, it cannot access the website.

Press the spacebar, then type the URL you want to block. Do not type “http://.” For example, if you want to block access to Facebook, enter “127.0.0.1 www.facebook.com.”

• The hosts file only checks for the exact URL you enter. For example, “google.com” only blocks the Google homepage. You can still access google.com/maps, google.com/mail, etc.
• Do not copy-paste from another document because there may be some invisible characters that make the text not work.

Add the URL to the new line. Press Enter and start a new line with 127.0.0.1 . Add after the URL you want to block. You can block any website, but must write new line with 127.0.0.1.

• In theory, you can add multiple URLs to a single line (enter the IP address once), up to 255 characters. ^[5] However, this doesn’t work on all versions of Mac OS X. ^[6]

Turn off and save the hosts file. Close or exit the TextEdit dialog when finished, then confirm you want to save the TextEdit file when prompted. (In some cases, the file will be saved automatically.)

• If editing in the main Terminal window, press ctrl + O to save, then press ctrl + X to close the file.

Clear cache. Type the command dscacheutil -flushcache into the Terminal and press Enter . This is a command to clear the cache, so the web browser will check for updates to the hosts file immediately. The website listed will be blocked on all browsers.

• You can restart your computer instead of clearing the cache. In many cases, the website will be blocked immediately without doing these actions.

Fix problem. If you can still access the website, chances are that your web browser is accessing another subdomain, either accessing it over IPv6 or passing through this web’s hosts file. You can fix the first two problems by adding the following lines to the hosts file:

• 127.0.0.1 (URL) without “www”
• 127.0.0.1 m.(URL) will block the mobile version of that website.
• 127.0.0.1 login.(URL) or apps.(URL) are some common variations of the homepage. Visit the website and check the address for accuracy.
• fe80::1%lo0 (URL) blocks access to the web over IPv6. Most websites don’t automatically connect via IPv6, but Facebook is an exception.
• If the above doesn’t work, the hosts file is probably not working. Try another method of blocking websites.

Delete the text to unblock the website. Open the hosts file and delete the line containing the URL you want to unblock. Save, exit, and clear the cache following the instructions in the step above to apply the changes.

• To undo the change and restore from a backup, press the key sudo nano /etc/hosts-original in Terminal. Press ctrl + O , remove “-original” in the name, confirm and save.

Install a web browser extension. Chrome, Firefox, and most modern browsers allow you to install extensions (or “add-ons”) that adjust your browser’s settings. Search for “block websites” or “filter websites” and “productivity” in your browser’s add-ons store to find apps that block websites. Install the application, restart the browser then open the application settings, add the website you want to block.

• Be wary of apps with low rating or few reviewers. Untrusted utilities can install malware on your computer.
• This method only blocks the website on the installed browser.