Modern Web browsers on a Mac, including Safari, Chrome and Firefox, automatically filter out pop-ups, but you can configure this aspect of the browser settings to allow all pop-ups or — in some cases — pop-ups from only certain sites. If you use third-party extensions to block ads, you can configure those similarly.
Allowing Pop-Ups in Safari
Configuring the Built-In Pop-Up Blocker
You can configure Safari in OS X Yosemite to allow pop-ups, which can be useful if a site you're visiting uses pop-ups to display useful content or ads that you want to see so the site earns more revenue.
Click the Safari menu and click the Preferences option.
Click the Security tab.
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Uncheck the Block Pop-up Windows check box.
Configuring External Extensions
Configure or disable pop-up blocking and ad-filtering extensions — or extensions of other types — in Safari through the Extensions Preferences menu.
Click on the Safari drop-down menu and choose Preferences.
Click the Extensions tab.
Click on an extension's name to configure it.
Uncheck the Enable check box to disable an extension, click the Uninstall button to remove it from Safari, or click the configuration options check box to see more options. Some extensions let you limit their effects to certain websites or specify the types of ads they filter.
Allowing Pop-Ups in Firefox
Configuring Firefox's Pop-Up Blocker
In Mozilla Firefox, you can configure the pop-up blocker to allow all pop-ups or only pop-ups from specific sites.
Click the Open Menu button.
Click the Preferences button.
To allow pop-up windows on all sites, uncheck the Block Pop-up Windows box. To allow them from only certain sites, leave the box checked and click Exceptions.
Within the Allowed Sites screen, type the name of a site from which you want to allow pop-ups and then click Allow.
Configuring Third-Party Plug-Ins
You can configure third-party ad-blocking plug-ins to allow ads from certain sites or disable them altogether.
Click the Open Menu button, and then click Add-ons.
Click the Extensions tab.
Click the Disable next to a particular extension to turn it off. Click Preferences to configure its options.
Allowing Pop-ups in Chrome
Configuring Chrome's Pop-Up Blocker
You can configure Google Chrome's built-in pop-up blocker to allow pop-ups from all sites or from only certain sites.
Click Chrome's Menu button and then click Settings.
Click Show Advanced Settings in the Settings menu.
Click the Content Settings button.
To allow pop-ups on all sites, click Allow All Sites to Show Pop-ups. To allow pop-ups from certain sites, click Manage Exceptions.
To allow pop-ups from a particular site, type its address into the text field. To allow pop-ups from any subdomain of a particular site, type [.] before the domain name, as in <a href="http://[.]example.com">http://[*.]example.com.
Configuring Chrome Extensions
Configure Chrome ad-blocking extensions through the extensions menu or through the toolbar menus.
Click the Window menu in Chrome and choose Extensions.
Uncheck the Enabled box next to an extension to disable it.
Some extensions ad a configuration button to the Chrome toolbar. Click an extension's toolbar icon to see additional options.