Connect the modem to power and your internet line

Start by placing your modem in a central location in your home — ideally near where your internet line enters the building. Avoid enclosed spaces like cabinets or closets, which trap heat and slow the connection. Keep the modem away from microwaves, cordless phones, and other wireless devices that can interfere with the signal.

Plug the power cable into the back of the modem, then into a wall outlet. You will see lights begin to flash on the front panel. Next, take the coaxial cable (the thick cable with a threaded connector) that comes from your wall outlet or cable box and screw it firmly into the port labeled "Cable In" on the back of the modem. Hand-tighten only — do not use a wrench.

Wait two to three minutes for the modem to fully boot up. The lights on the front will cycle through different colors. When the "Online" or "Internet" light turns solid green or white, your modem has connected to Xfinity's network and is ready for the next step.

Key Takeaways

  • Place your modem in a central, open location away from other wireless devices and metal objects that block the signal.
  • Connect the coaxial cable from your wall outlet to the "Cable In" port and plug in the power cable, then wait for the Online light to turn solid green.
  • Open a web browser and go to 10.0.0.1 or xfinity.com/authorize to reach the modem's setup page without needing to know your password.
  • Connect your devices to the Wi-Fi network name and password printed on the modem's label, or change them in the setup page to something you prefer.

Access the modem's setup page through your browser

Open any web browser on a computer or phone that is already connected to the internet (use your phone's cellular data if needed). In the address bar, type 10.0.0.1 and press Enter. This takes you directly to your modem's control panel without requiring a password.

If that address does not work, try going to xfinity.com/authorize instead. Either route will show you a page with your modem's current settings and Wi-Fi network information. If you see a login screen asking for a username and password, the default is usually admin for both, but most newer Xfinity modems skip this step entirely.

Connect your devices to the Wi-Fi network

Look at the label on the bottom or back of your modem. It lists your Wi-Fi network name (also called the SSID) and the password. On your phone, tablet, or computer, open the Wi-Fi settings and select the network name from the list. Enter the password exactly as shown on the label — it is case-sensitive and includes numbers and special characters.

Once you enter the password correctly, your device will connect and show a checkmark or "Connected" status. Repeat this step for every device you want to use on your home network. You can connect as many devices as you need; Xfinity modems typically handle 50 to 100 devices without slowing down noticeably.

Change your Wi-Fi name and password (optional)

The default Wi-Fi name and password printed on your modem work fine, but many people prefer to create their own. Go back to the modem's setup page at 10.0.0.1, then look for a section labeled "Wi-Fi" or "Wireless Settings." Click the option to edit or change your network name and password.

Choose a network name that is straightforward to remember but does not reveal personal information — avoid using your last name or address. For the password, use at least 12 characters mixing uppercase letters, lowercase letters, numbers, and symbols. Write down your new password and store it somewhere safe, because you will need it to connect new devices later.

After you save the changes, your modem will restart. The Wi-Fi will drop for 30 seconds to two minutes. When it comes back online, you will need to reconnect all your devices using the new password.

Restart the modem if the connection drops

If your internet cuts out or becomes very slow, restart the modem before calling Xfinity support. Unplug the power cable from the back of the modem and wait 30 seconds. Plug it back in and wait three to five minutes for the Online light to turn solid green again.

Do not hold down the reset button on the back of the modem unless you want to erase all your settings and start over. A straightforward power cycle (unplugging and plugging back in) fixes most temporary connection problems and takes only a few minutes.

Check your connection speed and signal strength

Once your modem is online and your devices are connected, you can check whether you are getting the internet speed you are paying for. Go to speedtest.net or fast.com on any connected device and run a speed test. The results show your read speed, upload speed, and ping time.

Compare these numbers to the speed tier in your Xfinity bill. If your speeds are significantly lower — more than 20 percent below what you are paying for — restart the modem first. If speeds remain low after a restart, the problem may be with your coaxial cable, the line coming into your home, or the modem itself. Contact Xfinity support with your speed test results to troubleshoot further.

Frequently Asked Questions

What do the lights on the front of my modem mean?

The Online or Internet light should be solid green or white when everything is working. A blinking light means the modem is still connecting or has lost the connection. Red or no light at all means the modem cannot reach Xfinity's network — check that the coaxial cable is screwed in tightly and wait a few minutes for it to reconnect.

Can I use my own modem instead of the Xfinity one?

Yes, but you need a modem that is certified to work with Xfinity's network. Check Xfinity's list of approved modems on their website before buying. You will still need to contact Xfinity to register your modem's MAC address so it can connect to their service.

Why is my Wi-Fi slow even though the modem says it is online?

Slow Wi-Fi usually comes from the modem being too far away, blocked by walls or metal, or interference from other wireless devices. Try moving the modem to a higher, more central location. You can also restart the modem, or check in the setup page whether your devices are connected to the 5 GHz band (faster but shorter range) or the 2.4 GHz band (slower but longer range).

Do I need to do anything special if I move to a new house?

Contact Xfinity before you move to have them transfer your service to the new address. When you arrive, set up the modem the same way — connect the coaxial cable from the wall outlet, plug in power, and wait for the Online light. The modem will automatically register with Xfinity's network once it detects the service is active at that address.

What if the setup page at 10.0.0.1 will not load?

Make sure you are connected to your modem's Wi-Fi network, not a different network. If you are on Wi-Fi and the page still will not load, restart the modem by unplugging it for 30 seconds. If the page loads but shows an error, try clearing your browser's cache or using a different browser entirely.