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Comcast Xfinity vs. ADT: Which professional home security system is better?

Between a cable company and a brand synonymous with home security, you'd think this wouldn't be a close call.

Dale Smith Former Associate Writer
Dale Smith is a former Associate Writer on the How-To team at CNET.
Dale Smith
5 min read

You might think home security titan ADT would crush Comcast's Xfinity Home Security system when pitting Xfinity versus ADT. After all, everyone hates cable companies, and Comcast customers seem especially loathsome toward their broadband provider. Their vitriol, however, doesn't seem to carry over to Xfinity's Home Security services. At least not in our testing, which convinced us Xfinity is a formidable contender in the professionally installed smart home security market.

But ADT has been around since before electricity -- literally. The company started a home protection service in the late 1800s, employing a team of security guards dubbed the Roundsmen who -- you guessed it -- made nightly rounds, checking on customers' homes. If anything, you might worry ADT might be stuck in a low-tech rut, but the company doesn't seem to have dragged its feet at all when it comes to innovation -- its technology is as cutting-edge as any competitor's.

So, what, then, differentiates Xfinity Home Security from ADT's service? The answer comes down to one of the oldest technologies in the world -- money. But it's not just the initial setup costs we're looking at, nor is it strictly the monthly service bill (although ADT's pricing in both of those categories is more expensive than Xfinity's).

We'll explain more fully in a bit, but first, let's look at what Comcast Xfinity has to offer.

Angela Lang/CNET

Unlike ADT, which is available pretty much coast to coast and beyond, Xfinity Home Security is limited to areas serviced by Comcast's broadband arm, Xfinity. That doesn't mean you have to also subscribe to Xfinity's broadband service (or, for that matter, its cable TV) -- Xfinity Home Security is compatible with any broadband provider (although you may get a package discount if you are a Comcast broadband customer).

Xfinity offers most of the same essential devices for building out a home security system -- door and window sensors, motion sensors, smart plugs, smoke detectors, security cameras and more, plus a touchscreen hub to tie it all together. Xfinity's list of devices with which its service integrates reads like a who's who of top smart home brands -- Lifx, Philips Hue, Chamberlain MyQ, August, Yale, Kwikset and more. The one notable exception is that there's no compatible doorbell camera like Ring or Nest Hello to pair with an Xfinity system.

A starter kit will set you back anywhere from $360 to $600, and you can expect to shell out upward of $1,000-$2,000 total on equipment, depending on how many a la carte devices you want to add (cameras and Xfinity's Zen Thermostat are the priciest options at $120, but most other devices will run you around $20 to $50 apiece). While far from bargain-bin prices, of all the professionally installed security systems we've tested, Xfinity's setup costs are the lowest overall.

Similarly to other companies (including ADT), Xfinity will let you spread that initial cost out over a period of time, typically 24 months, with installments paid at the same time as your monthly service charge, which can cost either $30 for basic service or $40 if you want to save your camera recordings.

Although this can all quickly add up to a monthly bill well over $100, here's the actually somewhat cool part: There are no contracts, so you can pay off your equipment costs and cancel at any time. Now, if only ADT's service were that simple.

Read our full Xfinity Home Security Review here..

David Priest/CNET

For a company that began at the dawn of the automobile era, ADT's devices and service are as cutting-edge as anyone's, including Xfinity's. Just as ADT's earliest human sentries were at some point replaced by wired electronic monitoring systems, most of ADT's equipment is now wireless. However, equipment only tells half the story -- thankfully, the way ADT allows you to operate it has been likewise modernized.

A crucial element of a contemporary smart home is how (and how well) your system executes routines (like turning off lights and setting the thermostat in advance of bedtime) and automations (when one action triggers another, like when unlocking a door triggers a light to come on). Although a bit hackneyed in its execution (some functions can only be accomplished on the website, for instance), there are few if any functions you can get a smart home security system to do that you can't also accomplish with ADT.

As far as pricing goes, ADT is on the high side of competitive -- and not just a little high, either. Depending on the equipment you choose, you could wind up paying almost twice as much for your initial setup as with Xfinity (or, for that matter, the other major national competitor, Vivint). Same goes for ADT's monthly service plan options -- in a market where $30 to $40 per month for professional monitoring service is par for the course, ADT charges as much as $60 per month if you want full use of all those fun features we mentioned (namely, automations).

But that's not the worst of it. No, the thing that sets ADT apart (in a bad way) and lands the company at the bottom of our list of best security systems is that ADT requires you to sign a contract. Before ADT will install and monitor your home security system, the company requires you to sign up for anywhere from 12 to 60 months of service and hammers you with a cancellation fee that can run as high as 75% of the remaining balance due according to your contract. 

Read our full review of ADT home security here..

Conclusion: Xfinity is still our favorite professionally installed security system

Just to be clear, Xfinity's win this round doesn't totally hinge on the whole contract/no contract dichotomy. Not all of ADT's contract terms are exploitive or unreasonable, especially if you're spreading the cost of equipment out over a term of equal length. It's more of a "hair that broke the camel's back" sort of thing.

Really, Xfinity beats ADT because it's less expensive both initially and over the long term, plus the tech is as good or better than what ADT offers, plus the user experience is better overall, with most functions being accomplishable no matter how you interact with the system.

Some customers may remain unconvinced that it's worth the added expense to forgo the DIY route and pay for the professional installation of a home security system. But if you're sold on the professional installation approach, the best service and value among the competition is Xfinity's.