Best local in-wall relays for Home Assistant
The best hidden relay modules for local-first smart homes, especially when you want to keep existing switches and still get strong Home Assistant control.
In-wall relays are the part of the smart home market that feels the most like contraband competence.
They don’t photograph well. They aren’t beginner-friendly. But they can be a better answer than replacing every wall switch in the house with expensive branded hardware.
Two picks that hold up:
- Best Wi-Fi relay for flexible local control: Shelly Plus 1
- Best Zigbee relay for older homes without neutral wires: SONOFF ZBMINI-L2
Quick verdict
If you’re comfortable with wiring and want the most flexible local-control option, buy Shelly Plus 1.
If your home has no neutral at the switch box, the SONOFF ZBMINI-L2 is the easier recommendation because that one detail decides a lot of real installs.
How we judge relays
Relays aren’t just about whether they switch power on and off.
We care about:
- How strong the local control story is
- Whether the install is realistic for older homes
- How well the relay fits Home Assistant
- Whether the product adds Wi-Fi clutter or strengthens an existing Zigbee mesh
- Whether it’s a sane way to preserve normal wall-switch behavior
Best flexible local-first pick: Shelly Plus 1
Shelly Plus 1 is the stronger general recommendation when the wiring situation allows it.
Why it stands out:
- excellent local APIs and MQTT support
- great Home Assistant fit
- tiny size makes it practical behind existing wall controls and in junction boxes
- affordable enough that it scales beyond a single “test” install
Why I would hesitate:
- it’s still an advanced install, not a casual one
- Wi-Fi-only devices add more load and clutter to your wireless environment if you use them everywhere
Best old-house relay: SONOFF ZBMINI-L2
The SONOFF ZBMINI-L2 matters because a lot of older homes don’t have a neutral wire where the switch lives.
That turns many otherwise-good relay ideas into dead ends.
Why this one earns a place:
- no-neutral support is a real practical advantage
- fully local Zigbee behavior
- doubles as a Zigbee router, which is useful instead of wasteful
Its main tradeoff is obvious: you need a Zigbee coordinator, and the install is still not for people who shouldn’t be touching mains wiring.
Wi-Fi vs Zigbee for relays
This is one of the places where protocol choice matters.
Choose Shelly Plus 1 if you want:
- flexible local APIs
- strong MQTT workflows
- no extra coordinator requirement
Choose SONOFF ZBMINI-L2 if you want:
- no-neutral compatibility
- fewer Wi-Fi devices
- a relay that also helps your Zigbee mesh
What to avoid
Avoid in-wall products if:
- you’re not comfortable with mains wiring
- you can’t verify the wiring situation first
- you really just want an easier smart switch replacement
A relay is often the best tool only when you specifically want to keep the existing switch hardware or solve an awkward electrical case.
Final recommendation
For most advanced DIY Home Assistant users, Shelly Plus 1 is the most flexible and compelling relay here.
For older homes or no-neutral switch boxes, buy SONOFF ZBMINI-L2.
Product notes:
