Comcast pop-up ad

The address cp-webapp.wifi.connected.xfinity.com  from the Pop Up image indicates that the message is associated with Xfinity/NOW WiFi, but the important question is whether it is appearing as a Safari pop-up, a website notification, or from a separate web app or background item.

First, in Safari go to Safari > Settings > Websites > Pop-up Windows. 

If an Xfinity-related site is listed, select it and choose Block. You can also set “When visiting other websites” to Block. 

Apple’s instructions are here: Allow or block pop-ups in Safari

Next, go to Safari > Settings > Websites > Notifications. 

If an Xfinity-related site is listed, select Deny. Also deselect “Allow websites to ask for permission to send notifications.” 

Then go to Apple menu > System Settings > Notifications and look under Application Notifications for Xfinity or another related entry. 

If present, select it and turn off Allow Notifications. Apple specifically states that website notifications can appear even when Safari is not open. (Apple Support)

Then go to Safari > Settings > Privacy > Manage Website Data and search for Xfinity, xfinity.com, or wifi.connected.xfinity.com. 

Remove the related website data. This can sign you out of Xfinity websites, but it clears the stored data associated with them.

Because the address contains cp-webapp, check your Applications folder and Dock for an Xfinity/NOW WiFi web app. 

A Safari web app operates independently of Safari and can have its own website data and notifications. 

If you find one you do not need, remove it. Apple’s instructions for Safari web apps are here: Use Safari web apps on Mac 

If the message continues to appear when Safari is completely closed, check Apple menu > System Settings > General > Login Items & Extensions. 

Look for an Xfinity-related application under Open at Login or Allow in the Background. 

Only disable or remove an item if you recognize it as being associated with Xfinity/NOW WiFi. Apple describes these settings here: Open items automatically when you log in on Mac 

Finally, check Safari > Settings > Extensions and disable or remove any extension you do not recognize or no longer use. 

Apple recommends checking Safari extensions and unexpected applications when persistent pop-ups continue. (Apple Support)

If the message still appears after these steps, the most useful next observation is whether it appears with Safari completely quit. 

If it does, the problem is not an ordinary Safari pop-up, and the next investigation should concentrate on the Xfinity web app, macOS notifications, or a background/login item rather than Safari's pop-up settings.

That depends on how you’re getting the ads.

Those ads might be notifications, might be advertising in a subscribed calendar, or might be ads displayed by some Xfinity Comcast app that’s been installed, ads displayed by ad networks while browsing, or something else.

You can post a screenshot of an ad, making sure ro remove anything sensitive before posting.

• Take a screenshot on Mac - Apple Support

Did Xfinity Comcast possibly set themselves as your Safari homepage?

• Change your homepage in Safari on Mac - Apple Support

Ammie wrote:

Thanks for your response. This is the ad I get on my desktop every time I open my browser (Safari). It doesn't happen if I use Chrome, but I almost always use Safari.

+1 MrHoffman is spot on.

All you need to do is change Safari to a different webpage, then set that as your Homepage.

Ref: Change your homepage in Safari on Mac - Apple Support

Thanks for your response. This is the ad I get on my desktop every time I open my browser (Safari). It doesn't happen if I use Chrome, but I almost always use Safari.

Thank you, all. Problem solved!