Can I use 2 routers on my home network?

Don't use 2 routers, they will conflict (without careful configuration) and even when they don't there is nothing to be gained by doing it.

A few things:

• The AirPort Extreme does not have a built-in modem, so you cannot directly replace the Xfinity gateway with it.
• What is the exact make & model of the Xfinity gateway? It may, or may not be, "better" than the AirPort Extreme.
• Which exact model of the Extreme do you have?

I do not recommend using a splitter. You'll reduce cable input signal. Price does not dictate whether or not one router brand is better than another. Look up the specs for both and that will show which is better.

I'm with Csound1 in that two routers can conflict.

Wireless Range Extender? (Not the "As Seen on TV" type.)

Cheers!!

The Arris is an extremely capable router. I wouldn't necessarily consider it "better or not better" than the 802.11ac AirPort Extreme.

I would suggest that you continue to use the Arris as your "main" router as it also has a built-in modem; the Extreme does not.

You can then decide what you want to use the Extreme for. If the goal is to use it to extend the wireless range of the Arris, then the only method to do so would require that they are interconnected by Ethernet, and then, both of them would need to be configured for a roaming type network.

With this type of network, each router will broadcast their own Wi-Fi network, but since they will all use the same network name, security type & password, wireless network clients will see them as a "single" network.

The Arris will produce WiFi speeds up to 300 Mbps. The AirPort will produce WiFi speeds up to 1300 Mbps. If connection speed capability is important to you, then the AirPort is "better" than the Arris.

If wireless range is important you, the only way that you will know whether one product is "better" than another is try them both out in your home.

Get the Arris up and running, if you have not already done so. Connect an Ethernet cable from one of the four LAN <--> ports on the Arris to the WAN "O" port on the AirPort, and set up the AirPort with a wireless network name and password of your choice.

Connect your computer to the WiFi signal from the Arris and test out the connection. If you have a laptop, move it to the furthest point away from the Arris that you plan to use and check the connection that way.

Then, connect your computer to the WiFi signal from the AirPort and test out the connection. If you have a laptop, move it to the furthest point away from the AirPort that you plan to use and check the connection that way.

Decide on which device you want to use, then turn off the WiFi service on the other product, since you probably don't need two wireless networks......unless.....you want to designate one of them for guests or the kids.

Your Internet Service Provider has a list of supported Cable Modem model numbers. I would suggest you contact your ISP to make sure the AirPort Extreme is one of the models supported by them.

Otherwise, WiFi coverage in your Home or Business either or ( AirPort or Xfinity ) will do the job. You will note that your Xfinity Specs allow use of Windows PC and MacOS for Set-Up. That is good. Some routers require Windows Only.

Configuring two routers for extended range varies with Brand and Model. You will have to research and read up on doing this. As Csound1 told you, which I have done and concur with him, if there is a conflict or not, I do not think it pays off with the trouble. Read the instructions for doing this with Xfinity and AirPort Extreme. A Range Extender is the better way.

Cheers!!

Your Internet Service Provider has a list of supported Cable Modem model numbers. I would suggest you contact your ISP to make sure the AirPort Extreme is one of the models supported by them.

Although it may just be a mix of terms, but the AirPort Extreme is a router and not a modem. I understand that sometimes the use of router and modem has been used to mean the same thing. They are not. In this case, the OP has a combination modem & router or gateway device. It's the modem compatibility that the ISP can assist with, not the router.

You will note that your Xfinity Specs allow use of Windows PC and MacOS for Set-Up. That is good. Some routers require Windows Only.

Most routers use a web-based administration interface. This can be accessed from Windows, OS X, or Linux clients. Only the Apple routers use a dedicated software application, called AirPort Utility. There are versions of this utility for OS X, Windows, and for iOS devices.