Z-Wave vs. ZigBee

A short smart home refresher course before we start: A smart home or home automation system is a collection of home devices that work together to provide useful functions such as automation and interoperability. The backbone of such systems is the wireless standard used to interconnect the devices. For the most part of the 21st century by far, those wireless standards are either Z-Wave or Zigbee.

You can think of Z-Wave and Zigbee as languages. When two devices speak the same language, they can connect and work with each other. That’s the building block of every smart home. So if you’re trying to make your home smart, the first step is to decide which smart home language to use. That is, you have to choose between Z-Wave and Zigbee.

We’ll help you do that by comparing the two wireless smart home standards and their capabilities in terms of security (i.e. encryption), speed, compatibility, and other critical factors. Having used devices that use both standards though, we can confidently say that both are good options. It just depends on what you’re trying to accomplish.

Z-Wave

According to Z-Wave marketing material, over 35 million different devices sold today use Z-Wave wireless standards. It is a proprietary technology that requires a license for companies to incorporate in their products. That means manufacturers need to pay royalty fees to use Z-Wave, which might affect its adoption as new, open-source standards like Matter start to gain traction. If Matter takes hold, we might see the number of Z-Wave devices drop in the future. But at least for now, you have plenty of brand and device options if you choose Z-Wave.

Z-Wave operates on a low-frequency radio band, 908.4 MHz in the United States. Since it is so low 0n the frequency spectrum, Z-Wave does not interfere with any Wi-Fi network. It may, however, interfere with some cordless phones as they too work on low-frequency radio bands.

Z-Wave devices are not interchangeable outside the region where they are sold. American Z-Wave products will not work with European Z-Wave devices.

ZigBee

ZigBee is an open-source protocol and available for free, just like Matter. And a quick fun fact: Although Matter was originally conceptualized by Apple, Amazon, Google, and the Zigbee Alliance, it is currently being maintained by the Connectivity Standards Alliance, which is the same alliance that maintains Zigbee. That could give Zigbee a slight edge over Z-Wave when it comes to market adoption.

ZigBee uses the IEEE 802.15.4 radiofrequency. It also can use 915 MHz in the United States but the limitations on data, 40 kbps maximum, makes it inefficient at this frequency. The 2.4 GHz frequency is also available to ZigBee. However, using this frequency may cause interference with Wi-Fi networks.

An important thing to note here is that even though Zigbee uses the same frequencies as Wi-Fi, the Zigbee smart home protocol is not the same as Wi-Fi security protocols. The main difference between Zigbee and Wi-Fi security is their purpose. Zigbee connects smart home devices to each other and to a central unit, also known as a hub, whereas Wi-Fi security protocols use various methods of encryption to secure your devices’ connection to your Wi-Fi router. We hope that clears things up.

Encryption

Each of the two major smart home appliance protocols uses AES-128 symmetric encryption. This sort of encryption is simple and effective and does not require any elaborate setup. It’s also plenty secure. While there have been reports of certain Z-Wave and Zigbee products being hackable in the past, those are isolated cases. In fact, the most famous case was the Z-Shave vulnerability discovered in 2018, and it wasn’t actually a Z-Wave vulnerability. It was an issue caused by how the manufacturer implemented Z-Wave in its smart locks.

So far, we haven’t heard of any major Z-Wave or Zigbee security vulnerabilities.

Speed

ZigBee is significantly faster than Z-Wave. It transmits data at 250 kbps compared to Z-Wave’s transmission rate of 100 kbps. This means Zigbee is capable of communicating more complex commands. That said, the speed difference between the two standards doesn’t affect the big picture. Since both wireless standards operate locally – meaning, the devices talking to each other are in close proximity – both Z-Wave and Zigbee won’t have a problem bouncing around commands and data between devices.

Compatibility

There are roughly the same number of devices compatible with Z-Wave and Zigbee, but Z-Wave has a major edge because all Z-Wave devices work with each other. In contrast, there are different Zigbee variants and some of them are not cross-compatible. That means buying devices with a Zigbee mark on it doesn’t guarantee that it will work with your smart home system.

Range and Costs

Even though ZigBee is faster and cheaper, since it is not proprietary like Z-Wave, one of the drawbacks is the range. ZigBee has a range of 35 feet whereas Z-Wave can transmit and receive at up to 100 feet.

This is somewhat mitigated by the ability of both protocols to mesh. If you have more than one ZigBee or Z-Wave device within close proximity, it will act as a repeater or booster and allow the signal to go further.

On that note, though, Zigbee has a superior meshing ability. It supports an unlimited number of hops, whereas Z-Wave only supports up to four.

For example, let’s say you have Zigbee devices lined up in a football field, one on each yard line. You want to send a command from the device on one end point to the device on the other end point. The signal will bounce from one yard line to the next until it gets to the end of the field. That’s possible because of Zigbee’s unlimited hops. With Z-Wave, the signal can only bounce up to the device on the 40-yard line – a total of four hops.

Zigbee’s meshing ability makes it a better option for larger properties and even commercial establishments.

Global Standard

Since ZigBee is an open-source protocol, which allows ZigBee products used in North America to be used in Australia or anywhere else in the world.

This does not necessarily mean interoperability. Any manufacturer can use ZigBee for free and when they do so, they often use software that is incompatible with another brand.

Z-Wave, since it is proprietary and only made by, or under license to, Sigma Designs, is made so that it can “talk” to any other Z-Wave component.

Final Thoughts

Both smart home device control protocols have certain advantages and disadvantages. It appears as though no one protocol has won the right to be called the standard. Z-Wave or ZigBee may ultimately win, but there are many other protocols developed or under development that may have more robust or attractive features that ultimately will push them to the top spot.