The Best SONOFF Smart Switches in 2026: 5 Models Compared for UK Homes

SONOFF has become the default starting point for UK homeowners who want smart switching without the premium price tag. Where rivals routinely charge £40–£60 for a single connected switch, a SONOFF smart switch can deliver Wi-Fi remote control, scheduling and app-based scenes for a fraction of that — provided you buy the right model for your wiring. That caveat matters more than the price. The range spans replacement touch wall panels, tiny modules that hide behind existing switches, budget inline relays, a four-channel controller and even a thermostat, and the neutral-wire situation in UK lighting circuits disqualifies several popular models without extra work.

This guide compares five of the most relevant SONOFF smart switches for UK homes in 2026, drawing exclusively on published sources: manufacturer spec sheets, verified owner reviews on Amazon UK, aggregate community feedback on Reddit’s r/homeautomation and the Tasmota device-template database. It is a research-based buying guide rather than a hands-on lab test, and every price below is an approximation that will shift between retailers and across promotions.

Quick Picks

How to Choose the Right SONOFF Smart Switch

The neutral-wire question comes first

The single most important fact for UK buyers is this: most UK lighting back boxes contain only a live and a switched live, with no neutral at the switch position. That instantly rules out any smart switch which requires a neutral. Of the five models here, the SwitchMan M5 and the Basic R2 both need a neutral connection, which makes them unsuitable for typical UK lighting retrofits. The Mini R4 is the workaround: per its spec sheet it supports a no-neutral mode, which is exactly why it keeps appearing in UK retrofit discussions and has become the default recommendation for older wiring. Before you buy anything, find out whether you have a neutral at the switch — it changes which models are even viable.

Match the form factor to the job

The five models are not interchangeable, and choosing the wrong one means either an awkward install or a wasted purchase:

• Wall-switch replacement — the SwitchMan M5 replaces your existing wall plate with a touch panel.
• Retrofit behind an existing switch — the Mini R4 hides inside the back box and keeps your current switch.
• Inline appliance control — the Basic R2 is wired into a circuit to switch whatever load sits on it.
• Multi-load control — the 4CH Pro R3 brings four independent relay channels in one module.
• Temperature-based control — the THR320 is a thermostat controller, not a relay, and belongs to a different buying decision entirely.

Respect the 10 A load ceiling

The Basic R2 is rated at 10 A, which is roughly 2,300 W at 230 V. A typical UK heater running at 2–3 kW therefore hits or exceeds that ceiling, which is a recipe for overheating and failure. Keep small relays for lamps, fans and electronics, and use a correctly rated controller for any heating load.

Connectivity: Wi-Fi, RF433, Matter and Tasmota

Chips differ from model to model — the Basic R2 runs an ESP8266, the Mini R4 an ESP32-C3 — so don’t assume a single chip across the range; for other models, check SONOFF’s own spec sheet rather than guessing. The Mini R4 is Matter-over-Wi-Fi native, meaning it can talk to Matter controllers over your existing Wi-Fi network without a separate hub. The 4CH Pro R3 adds RF433 reception alongside Wi-Fi, so it can be driven by a physical RF remote as well as the app.

Control happens through the eWeLink app, which SONOFF’s UK specialist retailer Hobby Components notes is hosted on Amazon AWS global servers, so you can monitor and switch connected devices from anywhere with an internet connection. Nearly every model also works with Alexa and Google Home through the eWeLink skill, which is the main reason SONOFF keeps appearing in budget smart-home setups.

For the tinkerers: both the ESP8266-based Basic R2 and the ESP32-C3-based Mini R4 have documented Tasmota community support, listed on the tasmota.io device templates page. Flashing Tasmota replaces the eWeLink firmware with open-source firmware, enabling local control and Home Assistant integration without cloud dependency.

The Best SONOFF Smart Switches for UK Homes in 2026

1. SONOFF SwitchMan M5 — Best Touch Wall Switch

The SwitchMan M5 is the model to choose when you want to replace a dated plastic light switch with a modern touch panel rather than hide electronics behind it. It comes in 1-, 2- and 3-gang configurations, so it can handle single or multiple lighting circuits from one wall plate, and it is the most feature-dense of the five models in this guide.

Per SONOFF’s official spec sheet, the M5 is available in two back-box formats: the 80-type measures 86 × 71 × 41.5 mm, while the 86-type measures 86 × 86 × 41.5 mm. The difference is the width of the fixing footprint, so you need to know which pattern your existing wall box uses before ordering.

There is a serious installation gotcha. The module is 41.5 mm deep, and SONOFF’s own specification makes clear that depth will not fit inside standard UK 16 mm or 25 mm plasterboard back boxes. A typical plasterboard back box simply doesn’t give the module room to sit flush inside the wall, so you would need a deeper back box or a surface-mounted installation. Check this before buying, not after the plaster dust settles.

The feature set, again from the manufacturer’s spec sheet, includes:

• timer and schedule routines for automatic on/off at set times
• multi-device group control, so one tap can switch lights across different rooms
• smart scenes that chain automations across the SONOFF ecosystem
• device sharing so other family members can control the switch
• an inching setting that auto-switches a load off after a set interval — handy for immersion heaters or fans you always forget to turn off

Like the Basic R2, the M5 requires a neutral connection per SONOFF’s specification, which rules it out for most UK lighting circuits unless you have a neutral at the switch. As with any hardwired smart switch in a UK dwelling, installation falls under Part P of the Building Regulations — a qualified electrician or self-certification is required.

The M5 is available from the SONOFF UK store at around £19–£21, and it is typically also stocked by Amazon UK and Hobby Components.

One-line verdict: the most capable wall panel in the range, but the 41.5 mm depth and neutral requirement make it a “check your wiring first” purchase.

2. SONOFF Mini R4 — Best for Retrofitting Behind an Existing Switch

The Mini R4 is the retrofit specialist. It is a compact relay module designed to sit behind your existing light switch inside the back box, so you keep the switch you already have and gain app control on top. From a UK perspective, this is arguably the most important model in SONOFF’s current range, because it solves the neutral-wire problem that rules out most alternatives for lighting.

The headline specifications, per the SONOFF Mini R4 spec sheet, are:

• ESP32-C3 chip
• Matter-over-Wi-Fi native — communicates with Matter controllers over existing Wi-Fi without a separate hub
• no-neutral mode — confirmed in the spec sheet
• designed to be installed behind an existing switch inside the back box

That no-neutral capability is the key differentiator. As covered above, most UK lighting back boxes have no neutral at the switch, and the M5 and Basic R2 both need one. The Mini R4 is built for exactly that scenario, which is why Reddit’s r/homeautomation community frequently notes it as the preferred no-neutral retrofit module. That is aggregate owner feedback rather than a lab finding, but it is consistent across threads and mirrors what UK installers keep saying.

Also notable for the technically minded: the Mini R4 (ESP32-C3) has documented Tasmota community support on the tasmota.io device templates page, alongside the Basic R2’s ESP8266.

The honest caveat is the installation. Because the R4 hides in the back box, you are working in a confined space with mains wiring — the fitting is fiddly, and Part P of the Building Regulations applies to the hardwired installation in a UK dwelling, so a qualified electrician or self-certification is required.

The Mini R4 typically costs approximately £10–£15 on Amazon UK, and is also usually available from Hobby Components and the SONOFF UK storefront.

One-line verdict: the no-neutral retrofit most UK homes actually need, with Matter support as a future-proofing bonus.

3. SONOFF Basic R2 — Best Budget Appliance Control

The Basic R2 is the model that put SONOFF on the map, and it remains the cheapest route into smart switching. It is an inline relay: you wire it into a circuit, and it switches whatever load sits on that circuit, with control through the eWeLink app. There is no wall plate and no touch panel — just a small module, usually tucked behind a socket or inside an enclosure.

Key facts, per the manufacturer’s spec sheet:

• ESP8266 chip, connecting over 2.4 GHz Wi-Fi
• rated at 10 A, which is roughly 2,300 W at 230 V
• no 433 MHz RF — if you want RF remote control, you need a different SKU, the Basic RF R2, not the Basic R2

That rating deserves emphasis. 10 A at 230 V gives you roughly 2,300 W, and a typical UK heater at 2–3 kW hits or exceeds that ceiling. Connecting one to a Basic R2 is asking for trouble. Use this module for lamps, fans, phone chargers, desk equipment and similar low-power loads, and treat heating appliances as out of scope.

What owners say: the Verified Purchase reviews on Amazon UK consistently cite value as the standout quality. For the money, there is very little else that offers genuine Wi-Fi switching, and the review consensus reflects that.

The price is remarkable: around £5–£8 on Amazon UK, or around £4 ex-VAT from Hobby Components, the Wolverhampton-based UK specialist retailer — the lowest typical price in this guide.

The caveats, to be clear: the Basic R2 needs a neutral, so it cannot generally be used for UK lighting retrofits; it lacks RF; and the 10 A ceiling puts heaters off limits. Wiring it into a fixed circuit in a UK dwelling falls under Part P of the Building Regulations — a qualified electrician or self-certification is required.

Where to buy: Hobby Components at around £4 ex-VAT, Amazon UK at around £5–£8, and the SONOFF UK storefront.

One-line verdict: astonishing value for low-power appliance switching, as long as you respect the 10 A limit.

4. SONOFF THR320 — Best for Temperature-Based Control

A note of caution first: the THR320 is a thermostat controller, not a relay switch. If your goal is simple app-based on/off of a lamp or appliance, this is the wrong model — it sits in a different competitive set alongside dedicated thermostats and temperature controllers, rather than alongside switches and relays.

What the THR320 does is temperature-driven control. It is designed for scenarios where a load — often heating or ventilation — needs to respond to temperature rather than to a manual tap in an app. Its distinguishing feature, per SONOFF’s published specification, is support for external temperature and humidity sensor probes. You can position the sensing element away from the unit itself, so the reading reflects the room or enclosure you are actually trying to control rather than the heat of the device or its immediate surroundings.

That matters in practice because a thermostat that measures its own case temperature can trigger early or late depending on where it is mounted. With external probes, the sensor goes where the condition matters — a greenhouse, a server cupboard, an outbuilding.

The caveat is that it will not give you the straightforward Wi-Fi relay switching the rest of the range offers. And if the THR320 is hardwired into a heating circuit in a UK dwelling, Part P of the Building Regulations applies — a qualified electrician or self-certification is required.

The THR320’s price varies by retailer, so it has no single typical figure; it is usually stocked by Hobby Components, Amazon UK and the SONOFF UK storefront, with pricing that differs between them.

One-line verdict: a niche but genuinely useful thermostat controller for temperature-led automation — not a general-purpose switch.

5. SONOFF 4CH Pro R3 — Best for Multi-Load and Motor Control

The 4CH Pro R3 is the multi-channel workhorse of the range, built for installations where one module needs to handle several loads. It provides four independent relay channels, so you can switch four separate circuits or devices from a single unit — think a gate, a garage light, a pump and an external socket, all controlled from one place.

Two connectivity options are on offer, per the specification: RF433 and Wi-Fi. That means you can control it through the eWeLink app over the internet, and also with an RF433 remote control for local, app-independent operation — a genuine advantage for gates and outbuildings where you want a physical keyfob rather than a phone.

The 4CH Pro R3 also includes two specialised operating modes that are rarely seen on budget relays:

• Inching mode — the relay energises for a set interval and then automatically switches off. The classic example is a gate motor: give it a pulse of power, let it run its cycle, then cut the power automatically.
• Interlock mode — channels are made mutually exclusive, so only one channel can be energised at a time. This matters where two loads must never run simultaneously, for example when reversing the direction of a motorised device.

The caveat is that this is a more involved installation than a single inline relay — four channels means more wiring into more circuits, so the Part P position is the same as for any hardwired mains work in a UK dwelling: a qualified electrician or self-certification is required.

Like the THR320, the 4CH Pro R3 has no single typical price — it varies by retailer, and the module is generally stocked by Hobby Components, Amazon UK and the SONOFF UK storefront.

One-line verdict: four channels, RF433 plus Wi-Fi, and motor-friendly modes — the right pick for gates, garages and multi-circuit setups.

UK Regulations and Practical Notes

Part P of the Building Regulations. Any hardwired mains work in a UK dwelling falls under Part P of the Building Regulations. In practice, that means the work must be done by someone competent and certified: either a qualified electrician who can self-certify their own work, or a homeowner who follows the formal self-certification and building-control notification route for notifiable work. A smart switch or relay module wired into a lighting or socket circuit is a fixed electrical installation, and it is not exempt simply because the device is small.

The neutral-wire reality. To recap the sharpest differentiator in this guide: most UK lighting back boxes have no neutral at the switch. That requirement alone rules out the M5 and Basic R2 for lighting duty; the Mini R4’s no-neutral mode is the workaround that makes a retrofit viable.

Where to buy in the UK. Hobby Components, based in Wolverhampton, is a named UK specialist retailer for SONOFF and is often the cheapest source — the Basic R2 at around £4 ex-VAT is a good example. SONOFF products are also available via Amazon UK and through SONOFF’s own UK storefront, and prices vary between the three, so it is worth comparing before you commit.

Frequently Asked Questions

Do SONOFF smart switches need a neutral wire?

It depends on the model. The SwitchMan M5 and the Basic R2 both require a neutral connection, while the Mini R4 has a documented no-neutral mode per its spec sheet. Most UK lighting back boxes have no neutral at the switch, so check your wiring before buying — and choose the Mini R4 if you are retrofitting lighting without one.

Can I use a SONOFF Basic R2 to control a 2 kW or 3 kW heater?

Not safely. The Basic R2 is rated at 10 A, which is roughly 2,300 W at 230 V, so a 2–3 kW UK heater hits or exceeds that ceiling. Use the module for low-power loads such as lamps, fans and chargers, and select a higher-rated controller for heating appliances.

Is the SONOFF Mini R4 Matter-compatible?

Yes. The Mini R4 runs on an ESP32-C3 chip and is Matter-over-Wi-Fi native, so it can communicate with Matter controllers over your existing Wi-Fi network without a separate hub. That makes it a more future-proof choice than older Wi-Fi-only modules.

Do SONOFF switches work with Alexa and Google Home?

Yes. You link your SONOFF account to Alexa or Google Home through the eWeLink skill, then control switches by voice or in the respective app. The eWeLink app itself is hosted on Amazon AWS global servers, so monitoring and switching work from anywhere with an internet connection.

Do I need an electrician to install a SONOFF smart switch in the UK?

Any hardwired mains work in a UK dwelling falls under Part P of the Building Regulations, so it must be done by a qualified electrician or through the self-certification route. Small smart modules wired into back boxes or consumer units are not exempt.

Can I flash Tasmota onto SONOFF devices?

Several models can, including the Basic R2 (ESP8266) and the Mini R4 (ESP32-C3), both of which have documented Tasmota support on the tasmota.io device templates page. Flashing replaces the eWeLink firmware with open-source firmware, enabling local control and Home Assistant integration without cloud dependency.

Which SONOFF switch should I choose if my back box has no neutral?

The Mini R4. Its spec sheet confirms a no-neutral mode, and Reddit’s r/homeautomation community frequently notes it as the preferred no-neutral retrofit option. The M5 and Basic R2 cannot be used for lighting in that situation.

The right SONOFF smart switch for your home comes down to three questions: is there a neutral at the switch, what are you switching, and how much load will it carry? If you are retrofitting lighting without a neutral, the Mini R4 is the obvious pick. If you are replacing a wall switch with proper wiring in place, the SwitchMan M5 delivers the most features. And if you just want the cheapest possible Wi-Fi relay for low-power appliances, the Basic R2 remains astonishing value. Whatever you choose, take the load rating seriously — and keep Part P in mind.