The coolest thing I saw at Google I/O is code that could eliminate smart home lag

Of all Google's announcements, the Local Home SDK could have the biggest and broadest impact. It could make all of your connected gadgets faster.

Andrew Gebhart Former senior producer
5 min read
James Martin/CNET

Google made a lot of announcements at the Google I/O developer conference, but there's a lot that goes on there that doesn't get mentioned during the livestreamed keynote presentation. The Nest Hub Max was the biggest announcement related to the smart home . It could be a great product, but it was during the developer's keynote presentation, held a couple of hours later in front of a much smaller crowd, where I saw a simple developer kit called Local Home SDK that will have a much larger impact on owners of any Google smart speaker or smart display.

I wrote about the Local Home SDK in detail at the time. In short, it allows Google's smart speakers and smart displays to send commands to third-party lights, video cameras , and gadgets directly via local wireless connections, rather than routing commands out through the cloud. Typically, if you give a command to a Google smart speaker, it processes the command in Google's cloud, then sends the data to the third-party cloud (so the Philips Hue cloud for Philips Hue bulbs, for example), which sends it down to the device.

Read more: Google is killing off the Works with Nest program in favor of Works with Google Assistant, and it could mess up your smart home set up.  

If device makers adopt Local Home SDK, it could skip the intermediaries and greatly improve the responsiveness of your smart home setup.

Watch this: The Google Nest Hub Max could teach you how to do anything with templates

Google Home -- a hub in disguise

Most traditional hubs, such as the SmartThings Hub, have built-in radios for low-frequency signals like Zigbee and Z-Wave. Zigbee and Z-Wave both use minimal power while sending a signal across distances large enough to cover most homes. This allows small gadgets like door sensors to communicate with hubs using these signals without consuming much battery life.

Traditional hubs have gradually fallen out of favor since Amazon popularized the smart speaker with the Amazon Echo. Hubs also made it simple to control many gadgets in a single app, but smart speakers make this process even easier for the whole family. Hubs tend to be ugly blocks of plastic that take up space on your router. Popular options like the Revolv have disappeared entirely, but smart speakers still haven't fully replicated the ability to streamline communication with small sensors so some hubs have remained.

Amazon replicated hubs to an extent with one of its smart speakers called the Amazon Echo Plus , which has a Zigbee radio. For Google, the Local Home SDK has the potential to streamline communication with a wider variety of connected gadgets, and it will work with all of Google's smart speakers and displays instead of just one model.


The original Google Home could soon double as a smart home hub.

Chris Monroe/CNET

SDK = Software Development Kit

When it launches in October, the Local Home SDK will be compatible with any type of device that currently works with Google Assistant -- the voice-activated digital helper built into Google's smart speakers, smart displays and phones. In theory, any of Google's 30,000 compatible gadgets could make use of the SDK.

Through the SDK, your Google device will store the data it needs to communicate with any accessory devices like smart thermostats. It will then send a signal over your own Wi-Fi network or via Bluetooth . Both Wi-Fi and Bluetooth are more common than Zigbee or Z-Wave and the specialized Bluetooth Low Energy is similarly easy on battery power.

You can control your gadgets with Google Assistant on your phone when you're on the road, and the SDK will use Google's cloud network to dynamically find the smart speaker with the right saved code. Using Google's side of the cloud command path is still necessary in this case since you'd be sending the command from outside of your home network, but the Local Home SDK will still bypass any third-party cloud transmissions and communicate directly from your Google speaker or smart display to the device you want to control.

Your Google Home will essentially act as a bridge, just like a hub. Owning a Google smart speaker or smart display becomes that much more important if you want to use Google Assistant to control your devices, as they'll be the key to speeding up response time through the SDK.

Here's everything that works with Google Home and Home Mini

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Thankfully, your third-party accessory won't actually be dependent on a nearby Google Home to work. The Local Home SDK builds on top of Google's traditional smart home codes instead of replacing them. Google will try the local shortcut if it can. If not, it will then send the signal through the third-party cloud as before. Even if the shortcut works, Google does update the third-party cloud of your device after it has responded to your command, so your Philips Hue app will correctly show the current state of your lights.

If a company employs the SDK and you already have one of their devices installed and set up with Google Assistant, it will automatically start using the SDK with no necessary input on your part. After the SDK officially launches in October, you could suddenly find that all of your smart home gadgets start responding with no lag.

The SDK will also allow you to set up compatible devices with the Google Home app, which will hopefully reduce the number of apps you need on your phone.

Necessary patience

Under ideal circumstances, the Local Home SDK would see rapid adoption at launch and you'd be able to use Google Assistant to set up and control a bunch of smart home gadgets with no noticeable delay. It's an appealing pitch, but realistically, it will likely take time for this new tech to catch on if it does at all.

Remember, Google Assistant works with 30,000 different devices spread across 3,500 brands. Granted, the SDK isn't officially live yet, but right now, only one brand actually uses it -- GE . Once the kit launches, Google will be asking its partner brands to do the heavy lifting to implement it, necessitating a lot of buy-in before the SDK starts to have a big impact.

The attractive element of Google's vision is the lack of any new proprietary signal protocols and the customer-friendly plan of turning a smart speaker you already have into a hub. If the SDK does catch on, it could finally render traditional hubs obsolete. It could make voice controls in the smart home faster than ever and you as the customer don't have to do anything to get this upgrade.

The biggest obstacle is buy-in from a varied industry, but the potential payoff is exciting enough for me to call Google Local Home SDK my favorite announcement of the Google I/O developer conference