Like self-driving cars, smart home tech is exciting because it’s convenient. Video doorbells let you see who’s there from anywhere — be it the couch or the other side of the country. Automated commands allow you to come home to illuminated lights, a disabled alarm, and a thermostat set to the perfect temp, all because you linked those actions with opening the garage door.

But smart home convenience turns inconvenient if your devices can’t communicate. When every tech company’s products speak a different language, a custom smart home turns into a Tower of Babel. Sidestepping the whole language barrier problem means sticking with the same brand for every device purchase, even if it’s not the best or most affordable option.  

You should be able to shop for devices across brands, weighing abilities and price points, not just logos. And tech companies agree. Through the Zigbee Alliance, Amazon, Google, Apple, and other big players are Zigbee Alliance to establish standard communication protocols for the smart home. In as little as a year, we could start seeing products that speak a universal tongue.

Hopefully, one day the question “What works with what?” won’t be worth asking. Secure, open-source communication protocols will allow devices to work together harmoniously. Until then, double check compatibility before you buy. Zigbee Alliance? Pick your home hub wisely, as the digital assistant it contains will serve as central command.

Smart Homes Need Smart Assistants

A single device to control your whole ecosystem— there’s a reason smart speaker usage is on the uptick. These voice-controlled hubs talk to all your connected devices, allowing you to make commands and trigger routines, or just ask if it’s going to rain. The voice assistant of your home hub or smart speaker will dictate what other devices you are best off buying.

  • Google Assistant pulls ahead in terms of sheer smarts. It answers more questions correctly according to “IQ” tests. That intelligence is a boon for offhand queries — the stuff you ask to direct you to the nearest coffee shop and help you cheat the crossword once you get there. But Google Assistant can’t complete as many diverse commands as Amazon Alexa. 
  • Amazon Alexa shines for its third-party skills, making it the stand-out option for smart home control. At Amazon’s most recent count, over 100,000 devices can be controlled with Alexa. Meanwhile, Google boasts over 30,000. Another feature that pushes Alexa into the winner’s circle: free home security. Just ask Alexa to go into Guard mode and the microphone will be on the alert for telltale noises of trouble, like breaking glass. 
  • As for Apple Siri — the most that can be said is that Siri is familiar. A built-in feature on Mac products, Siri is the voice assistant that many of us used first and use most, just by dint of availability (and inadvertent button pushing). But Apple’s smart home system HomeKit is limited and isolated. Interoperability and more devices may be on the horizon, but at this time, Siri can’t control nearly as many devices as Google Assistant or Amazon Alexa. It’s compatible brands list numbers just over 50. 
  • Samsung Bixby can answer nearly as many questions correctly as the reigning whiz kid Google Assistant, PC World Australia found, but it would be difficult to center your smart home around that assistant. Sure, a recent Galaxy phone could serve to access Bixby, and from there your connected devices, but Samsung has yet to release a home hub. (The company previewed its still-unreleased Galaxy Home in summer 2018.) Samsung itself recommends controlling SmartThings with Amazon Alexa or Google Assistant.  
  • Microsoft Cortana, too, is without a home hub to call its own. The best Microsoft can do: point you to the Harman Kardon Invoke speaker, or suggest you run Cortana on your PC, iPhone, or Android. Microsoft’s CEO admitted in January 2019 that he no longer sees Cortana as competitive with Amazon Alexa and Google Assistant. By that summer, the company’s vision for Cortana skewed toward business use.

If Apple rejoins the smart home race in earnest, we may have three viable voice assistant / home hub options for the smart home. But for now, Amazon and Google hold court. And of the two, Amazon, with its vast interoperability and outstanding skills list, more or less owns the smart home. But at every release event and quarterly report, all the horses are still in the running.  As Kevin C. Tofel with Stacy on IOT put it, “The smart speaker race continues to be run by Google and Amazon with Apple and Microsoft battling for the bronze medal.”

What Devices Work With…?

A lot of top smart home products are compatible with all four currently feasible smart home platforms. Others take a side. Note that a given brand or device may not be directly compatible with a given smart home platform, but could still be jerry-rigged to function with a middleman like If This Then That (IFTTT). This guide refers to plug-and-play compatibility. 

Here’s how 23 big names in smart devices and appliances play with the big platforms.

Amazon Echo / Alexa
Google Home / Assistant
Samsung SmartThings
Apple HomeKit / Siri
Z-Wave
Zigbee
Arlo
August
Belkin
Bose
NA
NA
Ecobee
GE
Honeywell
IKEA
iRobot
Siri only
Kwikset
LG
LIFX
Philips
Ring
Samsung
Schlage
Sengled
Sony
NA
NA
Sylvania
Vizio
NA
NA
Wyze
NA
NA
Xbox
NA
NA
Zmodo
NA
NA

What Home Security Systems Work With…?

A hybrid smart home / home security system makes the most out of home tech’s remote control and audiovisual capabilities. If you plan to use a home security system in concert with other devices, check for broad compatibility up front.

Zigbee vs. Z-Wave

Zigbee and Z-Wave are mesh networks: radio frequency networks, rather than WiFi or Bluetooth, that connect wireless devices. Zigbee has an outsized capacity for number of connected devices (tens of thousands) but for most homes, either Zigbee or Z-Wave (with a max of several hundred devices) will provide plenty of bandwidth. 

The primary difference: Zigbee is open source — interoperability is in Zigbee’s DNA. The Zigbee Alliance is formed by a group of over 500 technology companies. Z-Wave, on the other hand, is run by a private company, Silicon Labs. The more closed nature of Z-Wave means that fewer devices run on its network, but the communication between those devices is more reliable.

Both Z-Wave and Zigbee have announced plans to commit to open-source development. Z-Wave promises to open up its communication protocol to third-party developers by late 2020. Zigbee Alliance, already open source, is doing one better. The group will pull together the technology of its megastar members (Amazon, Apple, Google) to develop a truly secure, truly open communication protocol that resolves smart home tech’s two biggest issues: communication hang-ups and easily hacked devices. Connected Home over IP is slated for release to developers in late 2020, as well. 

Flexible Middleman: If This Then That (IFTTT)

Amazon Alexa, Google Assistant, and Samsung SmartThings all “work better with IFTTT” — a free, web-based service that allows you to string device commands together. (Of the top smart home platforms, only Apple HomeKit isn’t compatible with IFTTT.) Once called “recipes,” these bundled commands are now known as “applets.” Once you have connected devices, you can automate handy, but repetitive tasks like sending smart camera video footage to your phone, or flipping the lights off at bedtime. 

Pick Devices That Play Well With Others, Until All Can Play

While we wait for a standard, secure communication protocol for the smart home, you’re best off sticking with major tech brands for your central devices, and shopping off their compatibility lists for secondary devices. While you may spend a little more to stick with name brands, you’ll profit in time saved both setting up and using your smoothly connected home.