How to Child-Proof the Web on a Mac
You can find just about anything on the web. You've heard it a million times, but for parents, that truism takes on a whole new meaning. In this tutorial, I'll show you how to protect your family from the wild west of the web, using tools built right in to the Mac.
While there are many ways to do this, Parental Controls should go above and beyond the needs of most.
Screencast
Create a Managed Account



To get started, navigate to System Preferences and select Parental Controls. Here you'll see a basic overview of what Parental Controls is capable of controlling.
In order to begin making changes, you'll have to authenticate yourself to prove that you are, indeed, an administrator. This can be accomplished by clicking the small lock icon in the lower lefthand corner of the preference pane. Enter the administrator password and press Unlock.
Once unlocked, you'll be presented with a list of users that can be managed. Any non-administrator account can be managed using Parental Controls including the Guest User. If you need to add an account for a child, you can do so by pressing the small plus symbol, also located in the lower lefthand part of the window.
For families with more than one child, creating an account for each will allow a better look into each one's activities on the Mac. Just make sure that they each have unique passwords to prevent any sibling mischief.
Getting Started With Website Restrictions



Once you have set up managed user accounts, for the children, you can move on to setting up the individual restrictions on their web access.
Click on the account in the lefthand pane for which you'd like to set restrictions. Then, navigate to Web from the tab bar at the top of the window. Here you're given three distinct levels of control over the managed account. The first option, and the one that is selected by default, is to Allow unrestricted access to websites.
Don't worry, despite allowing unrestricted web access, it still provides the full suite of logging capabilities which I'll cover later. For a trust, but verify parenting style, this can be a powerful tool. Unfortunately, this leaves the onus on you to check the logs on a regular basis for objectionable material.
Automatic Filtering and SSL
The next level of control is something akin to the Goldilocks level: not too restricted, while also not too open. This makes it an ideal level of control for older children.
Select Try to limit access to adult websites automatically to enable this option. To work this magic, Apple uses the same basic text analyzing technology used in Mail to operate their Junk filters.
In addition, this filter also checks whether or not any given website identifies itself as adult-oriented using the RTA or SafeSurf rating systems. This option also forces children to use the Safe Search setting on search engines like Google or Bing.
For an increased level of control, you can also block or allow access to websites on a case-by-case basis. Do this by clicking the Customize… button below the Try to limit access… setting.
You'll be presented with two lists: one with sites to always allow and the other with those you'd like to always block. When doing either, it's important to note that the filter works on an extremely high level.
For example, it's impossible to block or allow access to a specific page on a larger website. Instead, the filter will block or allow the website as a whole. This precludes doing something such as only allowing specific YouTube channels. Once you're satisfied with your customized list, press OK to save the settings.



Unfortunately, this approach still has a few major flaws. First, if a page with adult content contains an unusually small amount of text, the filter might not detect this and allow it through.
Conversely, websites that are entirely safe may be mistakenly blocked by the filter. Perhaps the biggest flaw of the filter is its inability to examine the encrypted content of pages using SSL.
This includes popular sites like Google Drive, Gmail, Facebook and many more. Those sites generally begin with https:// instead of the more common http://. As a result, these sites will be blocked by default. Luckily, simply adding the desired site with its https URL to your list of always allowed websites will alleviate this problem.
Whitelist-Only Access
Thus far, I've covered options to either allow all websites or automatically filter some. While both are good choices for more mature children, parents with younger kids will be better served by whitelist-only access. This option will block all websites except those explicitly approved by you.
To enable this level of control, select the button next to Allow access to only these websites.
While Apple includes a few kid-friendly sites to get you started, using the plus or minus button beneath the list will allow you add or remove approved sites. These whitelisted sites are automatically added to Safari's Favorites bar for convenient access. As with other filtering modes, both visited and blocked sites are logged.
Limiting Preinstalled Apps That Access the Web
While all three methods outlined above help you manage your child's web access in one way or another, the Mac also can connect to the internet through its built in social apps including Game Center, Mail, and Messages. Parental Controls includes settings for these applications under the People tab.



You can effectively disable Game Center entirely by unchecking the boxes marked, Allow joining Game Center multiplayer games and Allow adding Game Center friends.
Both Mail and Messages include options to limit communications to allowed contacts. These can be enabled by checking the respective checkboxes.
The Allowed Contacts list is shared between both applications and can be managed using the plus or minus buttons in beneath the list. When adding a contact to the whitelist, you can either add them by name or browse through your address book by hitting the downward caret to the right of the Last name field.
Disable Apps With Web Access
As one final precaution, you'll want to disable certain apps with web access.
To do this, navigate to the Apps tab in Parental Controls. Check the box labeled Limit Applications. While there are a number of ways to limit applications, you'll be concerned with the Allowed Apps list. Simply uncheck any applications you're uncomfortable with.
It's a good idea to disallow third party web browsers like Google Chrome as they don't interface well with Parental Controls. While Parental Controls will still limit their web access, rather then being presented with an easy to understand error page as with Safari, your child will be hit with a confusing popup box when trying to access a blocked site through an alternative browser.
Go Further
Now that you've set up Parental Controls for one account, it's easy to apply them to others. In the lefthand accounts list, select the account whose settings you'd like to copy.
Next, click the small gear next to the add/delete accounts button. Finally, click Copy settings for… From there, simply select the account you'd like to apply these settings to and choose Paste settings to…



Once you've applied the proper Parental Controls for each child, viewing their access logs is easy.
Just select an account and choose Logs… in the bottom-right of the preference pane. Here, you're able to view logs for websites blocked, websites visited, applications, and even messages. As you're sorting through these logs, pressing the Block button will allow you to easily block specific websites or contacts.
Conclusion
With these tips in mind, you're now free to breathe a little easier knowing that your children won't be exposed to the darker side of the web. Let me know in the comments below which filters you'll be using to keep your family safe!