The Connectivity Standards Alliance (CSA) has announced Zigbee 4.0 alongside Suzi, a new brand for Zigbee’s long-range Sub-GHz capability. The headline features are the ones smart home users have been asking for: easier onboarding, stronger security, and the option to move beyond crowded 2.4 GHz in the future.
This was announced on 18 November 2025, and it’s positioned as a backward-compatible evolution, not a clean break. CSA says Zigbee 4.0 is fully backward compatible with Zigbee 3.0 and Smart Energy, while adding new tools aimed at modern networks and denser deployments.
Below is what’s actually new, and what it likely means if you’re running Zigbee at home today.
What’s new in Zigbee 4.0
CSA’s own release frames Zigbee 4.0 as improvements across three buckets: range options, security, and commissioning.
Sub-GHz support is now part of the Zigbee 4.0 story
Zigbee 4.0 adds support beyond 2.4 GHz, specifically calling out European 800 MHz and North American 900 MHz PHY options to improve range and coverage.
Important note for Aussies: CSA’s announcement names EU and North America specifically, so any Australia-specific Sub-GHz profile details will depend on how products and certification roll out. For now, treat Sub-GHz Zigbee as “coming”, not “on shelves next week”.
Security and network hardening got a real lift
CSA lists a stack of new security capabilities, including Dynamic Link Key, Device Interview, and Smart Energy Authentication Level Control, plus tools like Restricted Mode, Secured Channel, PAN ID Changes, and Trust Center Swap Out.
They also call out Advanced Frame Counter Synchronization to help prevent replay attacks, along with reliability improvements like standardised retries and better polling for sleepy end devices.
Batch Commissioning is aimed at bigger installs (but it’s still good news for homes)
Zigbee 4.0 adds Batch Commissioning, described as a way to set up multiple devices more efficiently across residential and commercial deployments.
If you’ve ever paired 30 devices one-by-one after a renovation or a big move, you already know why this matters.
“Setup direct from phone” is Zigbee Direct, and it’s a big deal
The “set it up from your phone” angle is largely driven by Zigbee Direct, which CSA describes as a Zigbee feature that lets users onboard and control Zigbee devices via Bluetooth Low Energy (BLE), using things you already have like a smartphone or smart speaker.
CSA’s press release is very direct about the goal here: onboard and control devices via BLE without a hub.
A couple of practical implications:
- This does not magically delete hubs from existence, Zigbee still needs a Zigbee network somewhere.
- It does mean manufacturers can offer a more familiar onboarding experience, and potentially reduce “why won’t this pair” friction.
If you want to go deeper, CSA has dedicated Zigbee Direct pages (and a FAQ) that explain the concept and the role of BLE devices in onboarding and control.
Suzi: Sub-GHz Zigbee gets its own brand
Alongside Zigbee 4.0, CSA introduced Suzi, described as the brand for standards-based wireless tech that extends Zigbee’s reach using long-range, Sub-GHz mesh networking.
CSA says Suzi is built on the Zigbee network layer and is intended to combine:
- long-range performance
- low power consumption
- multi-vendor interoperability
They also position it for use cases that struggle with 2.4 GHz coverage, like outdoor areas, larger buildings, and city-scale deployments.
When will Suzi products show up?
CSA says the Suzi Certification Program is planned to open in the first half of 2026
That’s a useful reality check: announcements are one thing, certified products you can actually buy are another.
What this means if you already run Zigbee at home
Here’s the part most people care about: should you worry about your current Zigbee setup?
Based on CSA’s announcement, Zigbee 4.0 is designed to be backward compatible with existing Zigbee 3.0 and Smart Energy devices.
So if you’re running Home Assistant with Zigbee2MQTT or ZHA, or you’re on a vendor hub today, the reasonable expectation is:
- Your existing Zigbee gear keeps working.
- You will gradually see Zigbee 4.0 devices appear that still operate on 2.4 GHz and should behave like “normal Zigbee devices” from a user point of view.
- Suzi (Sub-GHz) will be a separate capability that needs the right hardware and certified products.
The most exciting part, in my opinion, is that Zigbee is pushing hard on the two pain points that cause the most complaints: pairing experience and network stability in busy RF environments.