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For most Home Assistant setups the Shelly 1 Gen4 is the smart relay to buy: fully local over Wi-Fi, Zigbee, or Matter, no account required, and covered by the best-in-class native Shelly integration. If your switch box has no neutral wire, pivot straight to the SONOFF ZBMINI-L2; it is the only well-tested no-neutral Zigbee option that pairs directly with ZHA or Zigbee2MQTT and costs almost nothing. Z-Wave households get the Shelly Wave 1PM, a genuinely excellent alternative that runs fully local through Z-Wave JS and adds per-circuit energy metering in the same tiny body.
Quick picks
| Product | Best for | Price tier |
|---|---|---|
| Shelly 1 Gen4 | Best overall – multi-protocol Wi-Fi/Zigbee/Matter relay | Mid-range |
| Shelly 1PM Gen4 | Best with power metering | Mid-range |
| SONOFF ZBMINI-L2 (Extreme) | Best for no-neutral wire boxes | Budget |
| SONOFF ZBMINIR2 | Best Zigbee relay for smart-bulb setups | Budget |
| Shelly Wave 1PM | Best Z-Wave relay with energy monitoring | Mid-range |
What is a smart relay switch – and do you need one?
A smart relay hides inside the wall behind your existing switch or in a ceiling void. Your wall switch stays exactly where it is; the relay turns it smart. That is fundamentally different from replacing the switch with a new smart face plate. Relays are ideal when you rent, when the box is too shallow for a smart switch, when you want to keep a designer rocker, or when you need to control something that is not a light – garage doors, pumps, irrigation valves, and anything else with a switched circuit. If you are running Home Assistant and want zero cloud dependency, they are hard to beat. For a broader look at local-first Zigbee gear, our Best Zigbee Smart Plugs that double as Routers guide covers the plug-in side of the same philosophy.
The products
Shelly 1 Gen4 – Best overall smart relay
The Shelly 1 Gen4 is a single-channel in-wall relay that you can run over Wi-Fi, Zigbee 3.0, or Matter – whichever protocol fits your setup – and switch between them later without buying new hardware. It delivers a potential-free dry-contact output rated at 16 A, accepts 110–240 V AC or 12–48 V DC on the supply side, and fits behind virtually any existing wall switch or inside a junction box. The Gen4 replaces the now-discontinued Shelly Plus 1 and adds Zigbee, Matter, Wi-Fi 6, and Bluetooth 5.0 to the same proven form factor.
The native Shelly integration in Home Assistant is rated Platinum on the official quality scale and communicates entirely over your LAN using a local RPC/HTTP API; nothing touches the Shelly cloud unless you explicitly enable it. In Zigbee mode it also acts as a Zigbee router, strengthening your mesh as a side effect of the installation. Scripting, MQTTS, inbound and outbound WebSocket support, and KNXnet/IP communication are all available on-device for anyone who wants to go deep.
- Strengths: Three local paths into Home Assistant (official Shelly integration over Wi-Fi, ZHA/Zigbee2MQTT in Zigbee mode, or Matter); dry-contact output handles low-voltage loads and garage doors that most relays cannot; 16 A rating covers heaters and heavy circuits; built-in temperature sensor triggers an overheating protection cutoff.
- Drawbacks: Requires a neutral wire at the switch box – not an option for older two-wire UK or European wiring. No power or energy metering on this model; the 1PM Gen4 (see below) is the metered sibling. Early user reports note that Zigbee mode on Gen4 devices is still maturing and that configuration changes still require Wi-Fi access even when the device is operating in Zigbee mode.
Check price: Amazon UK | Amazon US | Amazon IE
Shelly 1PM Gen4 – Best with power metering
Identical in footprint, protocol stack, and Home Assistant integration to the 1 Gen4 above, the 1PM Gen4 adds per-circuit power metering. That means real-time wattage, voltage, and cumulative energy consumption appear as entities in Home Assistant the moment you add the device – no extra sensors, no extra wiring. Those entities slot directly into Home Assistant’s Energy Dashboard, so you can track exactly what each switched circuit is using. It supports the same Wi-Fi, Zigbee 3.0, Bluetooth, and Matter connectivity as the base Gen4, with the same 16 A dry-contact output and neutral-wire requirement.
- Strengths: Energy-aware automations without any additional hardware – trigger actions when a device finishes a cycle, track standby draw, or alert on anomalous consumption; all four radio protocols in a single module; excellent Home Assistant integration via local API or Zigbee2MQTT.
- Drawbacks: Neutral wire required, same as the base 1 Gen4. Slight premium over the non-metered version for a feature some lighter-use installs do not need. Zigbee-mode Shelly devices are still accumulating long-term user data compared with the battle-tested Plus series.
If you are already deep into energy monitoring across your whole property, our Best Home Energy Monitors for Home Assistant UK guide pairs well with per-circuit relays like this one.
Check price: Amazon UK | Amazon US | Amazon IE
SONOFF ZBMINI-L2 (Extreme) – Best no-neutral Zigbee relay
The ZBMINI-L2 is SONOFF’s answer to old wiring. It is a Zigbee 3.0 relay that installs without a neutral wire, which rules out most of the competition in one sentence. It is tiny – small enough to fit inside even cramped UK back boxes – and pairs directly with ZHA or Zigbee2MQTT in Home Assistant with no SONOFF account and no eWeLink app required. Once it is in Home Assistant it appears as a standard switch entity; the control loop is entirely local, so it keeps responding even when your Home Assistant server is mid-reboot. It is rated at 6 A / 250 V and supports standard toggle, momentary, and SPDT external switches.
- Strengths: The only widely-available, well-supported no-neutral Zigbee relay at a budget price; rock-solid ZHA and Zigbee2MQTT compatibility confirmed across large-scale installs; pairs with any Home Assistant Zigbee coordinator (SkyConnect, Sonoff dongle, or similar) with zero vendor app needed.
- Drawbacks: Does not act as a Zigbee router – every L2 is a Zigbee end device, so relying on it exclusively will not strengthen your mesh. The 3 W minimum load requirement means it can flicker or behave unexpectedly with very low-draw LED bulbs. No detach relay mode, so it is not suitable as a smart-bulb keepalive. Inductive loads such as fan motors are explicitly unsupported.
Check price: Amazon UK | Amazon US | Amazon IE
SONOFF ZBMINIR2 – Best Zigbee relay for smart-bulb setups
The ZBMINIR2 is the neutral-wire sibling of the ZBMINI-L2, and it fixes both of the L2’s biggest frustrations for Zigbee-first Home Assistant setups. First, it acts as a Zigbee router and can support up to 64 end devices, so every unit you install actively strengthens your mesh. Second, it has a Detach Relay Mode: the physical wall switch is decoupled from the relay output and fires as an event instead, which means smart bulbs behind the switch stay constantly powered and never drop off the network when someone touches the rocker. A Turbo Mode in Zigbee2MQTT boosts radio power for installs where signal reach is tight. The module is rated at 10 A / 2400 W and measures just 39.5 × 33 × 16.8 mm.
Zigbee2MQTT is the recommended integration path here – it exposes the full feature set including detach relay mode, turbo antenna mode, inching mode, power-on behaviour, and an external-trigger mode. ZHA works for basic on/off switching but users report that advanced features including detach relay mode are inconsistently exposed through ZHA alone. If you are pairing this with smart bulbs, see our Best Zigbee Light Bulbs for Home Assistant guide for compatible options.
- Strengths: Zigbee router that extends mesh coverage for up to 64 devices; detach relay mode keeps smart bulbs always-on; Turbo Mode for challenging installs; full local control through Zigbee2MQTT with no cloud dependency; budget price.
- Drawbacks: Neutral wire required. Detach relay mode and advanced features require Zigbee2MQTT – ZHA users get a less complete experience. No power metering.
Check price: Amazon UK | Amazon US | Amazon IE
Shelly Wave 1PM – Best Z-Wave relay
The Shelly Wave 1PM is what you reach for when your Home Assistant setup is built around Z-Wave rather than Zigbee. It runs on the Z-Wave 800 Series (S800) chipset, operates fully locally through the Z-Wave JS integration, and adds per-circuit power metering. The EU/UK variant is rated at 16 A; the US LR UL variant is rated at 15 A – both handle the vast majority of household circuits without issue. In standard mesh mode (Z-Wave Plus), the module doubles as a Z-Wave repeater, improving coverage across your network; note that Z-Wave Long Range mode, available on the US SKU, does not support repeating by design. SmartStart QR-code inclusion makes pairing fast and secure. Users across UK Amazon reviews consistently describe it as reliable and straightforward to wire, with solid Home Assistant performance out of the box.
One important regional note: the standard Shelly Wave 1PM sold on Amazon UK operates at 868.4 MHz, the CEPT frequency for EU and UK. For the US market, Shelly sells a separate SKU – the Shelly Wave 1PM US LR UL – which operates at 908/912 MHz. These are not interchangeable; using the wrong frequency variant in a region is illegal and will not work correctly with your Z-Wave controller. Always confirm you are buying the correct regional variant. For a broader look at Z-Wave sensors and local-control gear, our Best Recessed Z-Wave Door Sensors guide covers compatible accessories.
- Strengths: Z-Wave 800 Series for improved range and Security 2 Authenticated encryption; real-time and cumulative energy monitoring feeds directly into the HA Energy Dashboard; acts as a Z-Wave repeater in mesh mode; fully local via Z-Wave JS with no cloud dependency.
- Drawbacks: Requires a neutral wire. Needs a Z-Wave controller/hub – not a standalone device. Some users note a roughly half-second delay when triggering via the physical switch input compared with direct HA commands, which is a Z-Wave network characteristic rather than a hardware fault.
Check price: Amazon UK | Amazon US (search confirms the US-frequency SKU – look for ‘Shelly Wave 1PM US LR UL’ to verify the correct regional variant) | Amazon IE
Buyer’s guide: what to check before you buy
Neutral wire or no neutral?
This is the first question and it determines most of the shortlist. Open the switch box before ordering. If you see three or four wires including a neutral (blue in EU/UK wiring, white in North America), you have full choice. If there are only two wires – live in and switched live out – the SONOFF ZBMINI-L2 is the only relay on this list that will work. Everything else requires neutral.
Zigbee, Z-Wave, or Wi-Fi?
All three paths deliver fully local Home Assistant control when set up correctly. Zigbee is the cheapest entry point and works with a USB coordinator like the Home Assistant SkyConnect. Z-Wave adds a dedicated 800–900 MHz radio that sidesteps Wi-Fi congestion and has stronger mesh characteristics, but adds the cost of a Z-Wave controller. Wi-Fi (Shelly Gen4 in Wi-Fi mode) needs no hub at all and uses the native Shelly integration, which is Platinum-rated in Home Assistant – the trade-off is that your relay lives on your 2.4 GHz network. For a comparison of Zigbee hub options, see our Best Budget Zigbee Hubs guide.
Do you need detach relay mode?
If you are keeping smart bulbs on a circuit – Zigbee or Wi-Fi bulbs that need constant power to stay on the network – you need a relay with detach mode. That means the SONOFF ZBMINIR2 (via Zigbee2MQTT) or either Shelly Gen4 in detached input configuration. The ZBMINI-L2 does not support detach mode; turning the wall switch will cut power to the bulbs.
How we chose
Every product on this list was selected based on verified specifications from manufacturer pages and third-party teardown reviews, confirmed Home Assistant integration quality (ZHA, Zigbee2MQTT, Z-Wave JS, or native Shelly integration), and real user feedback from Amazon reviews and the Home Assistant Community forum. We prioritised devices with fully local control – no cloud dependency required for day-to-day operation – and excluded anything that requires a vendor app or cloud account just to function. Regional availability was checked individually for Amazon UK, Amazon US, and Amazon IE, with Z-Wave frequency variants confirmed before linking.
FAQ
Can I use a smart relay without replacing my existing wall switch?
Yes – that is the whole point of a relay. The module installs inside the wall box or ceiling void behind the existing switch. Your physical switch continues to work for manual control, while the relay adds remote, scheduled, and automation-based switching through Home Assistant.
Do Shelly relays need the Shelly cloud to work with Home Assistant?
No. The Shelly 1 Gen4 and 1PM Gen4 communicate with Home Assistant entirely over your local network using a local RPC API and WebSocket push. The Shelly cloud is opt-in and can be left disabled from initial setup. Even if Shelly’s servers go down, your relays keep working and Home Assistant keeps controlling them.
What is the difference between the SONOFF ZBMINI-L2 and ZBMINIR2?
The ZBMINI-L2 works without a neutral wire, is budget-priced, and pairs simply with ZHA or Zigbee2MQTT – but it does not act as a Zigbee router and has no detach relay mode. The ZBMINIR2 requires a neutral wire, adds detach relay mode (ideal for smart-bulb keepalive setups), acts as a Zigbee router supporting up to 64 end devices, and includes a Turbo Mode for stronger radio output. If your box has a neutral and you run Zigbee smart bulbs, the ZBMINIR2 via Zigbee2MQTT is the stronger choice.