Shelly 1 Gen3 Review: A Tiny No-Neutral Smart Relay That Does Almost Anything
A compact, no-hub Wi-Fi and Matter relay with dry contacts and deep scripting, for retrofits and DIY automation, with no energy monitoring.
The Shelly 1 Gen3 is a tiny, versatile smart relay that hides behind an existing switch or in a junction box to make almost any circuit smart, without a neutral wire or a hub. It works over Wi-Fi and Bluetooth, supports Matter, and integrates with Alexa, Google Home, Apple HomeKit, SmartThings and Home Assistant, with full local control (it can even run automations without the internet). Its dry and wet contacts and flexible 110-240V AC / 12-48V DC power make it a favorite for garage doors, pumps, irrigation, pool filtration and driving bigger relays, and it is deeply programmable (on-device scripts, even custom ESPHome firmware). The main gaps: there is no energy monitoring, it fits tight in small boxes (sometimes needing an extender), and complex installs need real electrical know-how. For DIYers, it is one of the best-value automation building blocks around.
- Retrofitting dumb switches
- No-neutral wiring
- Home Assistant and DIY automation
- Garage doors, pumps and irrigation
Pros
- Tiny: hides behind a switch or in a junction box to make any circuit smart
- No neutral and no hub required; works with the existing physical switch
- Dry and wet contacts plus 110-240V AC or 12-48V DC power for almost any project
- Matter support and integration with Alexa, Google, HomeKit, SmartThings and Home Assistant
- Full local control with on-device JavaScript scripting and ESPHome flashing
- OTA updates, low-power mode and reliable performance at a low price
Cons
- No energy / power-consumption monitoring (PM models add this)
- Tight fit in small boxes; may need extra wires or a box extender
- Complex DC/solar/power-relay installs require real electrical know-how
- No easy push notifications (you check the activity log)
- No DIN-rail mount and no built-in physical on/off button
- Wi-Fi/Bluetooth only (with Matter); no Zigbee, Z-Wave or Thread
Who is the Shelly 1 Gen3 for?
This is a single-channel smart relay for people who want to add smart control to existing wiring without replacing switches or running new cable. It is small enough to tuck inside a wall box, switch plate or ceiling box, requires no neutral and no hub, and works over 2.4GHz Wi-Fi and Bluetooth (acting as a Bluetooth gateway). It handles up to 16A and runs on 110-240V AC or 12V / 24-48V DC, with both dry-contact and wet-contact modes so it can switch or trigger almost anything. It supports Matter and integrates with Amazon Alexa, Google Home, Apple HomeKit, Samsung SmartThings and Home Assistant, with OTA updates and full local control. Crucially for tinkerers, it is highly programmable with on-device scripting (JavaScript) and can even be flashed with custom ESPHome firmware (it uses an ESP32-C3). It best suits DIYers retrofitting dumb switches, homes with no-neutral switch boxes, Home Assistant users, and projects like garage door openers, sump and pool pumps, irrigation and driving larger industrial relays.
What buyers love
The recurring praise is how small and versatile it is. Owners love that it fits behind an existing switch to turn a dumb circuit smart while still working with the physical wall switch, and that it solves no-neutral problems by wiring it into the ceiling box instead. The dry contacts make it a Swiss-army relay: reviewers use it for garage doors, sump and bilge pumps, pool filtration, irrigation, 3D printers and even to pilot heavy-duty industrial relays for solar battery management. Setup over Wi-Fi or Bluetooth is called easy (it handles a shared 2.4/5GHz SSID fine), and integration with Home Assistant, Alexa, Google and SmartThings is praised as seamless, with full local control so it can automate without ever talking to the cloud. Power buyers highlight the on-device JavaScript scripting and ESPHome flashing for custom logic and timers, the flexible AC/DC power options, a low-power mode that makes battery-powered projects last weeks, and overall reliability at a low price.
What to know before you buy
The most common gap is the lack of energy monitoring: if you want to track power consumption, this model does not do it (Shelly's PM variants do). It is compact, but in a crowded wall box it can be a tight fit, and some installs need extra wires or a box extender to make everything fit. Because it is a wiring device, simple lighting retrofits are easy, but more complex projects (DC systems, motorhomes, solar/battery, driving power relays) really do require electrical competence or a pro. There is no easy push notification when state changes (you check the activity log), no DIN-rail mount and no built-in physical on/off button. A few owners needed a full reset during pairing, and one noted an older Gen1 failed under a voltage spike, so respect the 16A limit and your load's surge behavior. There is no Zigbee, Z-Wave or Thread; it is Wi-Fi/Bluetooth with Matter.
Is the Shelly 1 Gen3 worth it?
For DIY smart-home builders, yes, emphatically: it is a cheap, tiny, no-neutral, no-hub relay that retrofits existing wiring, works with every major platform plus Matter, runs locally, and is programmable enough to handle projects far beyond simple lighting. The flexibility (dry contacts, AC or DC power, scripting, ESPHome) is what makes it a staple in the community. Skip it only if you specifically need energy monitoring (choose a PM model), a DIN-rail form factor, or you are not comfortable working with mains or low-voltage wiring. Otherwise, as a versatile automation building block at this price, it is hard to beat.
Frequently asked questions
Does the Shelly 1 Gen3 need a neutral wire or a hub?
No to both. It does not require a neutral wire and works without any hub, connecting directly over Wi-Fi (and Bluetooth). This makes it a common fix for no-neutral switch boxes, often by wiring it into the ceiling box.
Which smart home platforms does it work with?
It supports Matter and works with Amazon Alexa, Google Home, Apple HomeKit, Samsung SmartThings and Home Assistant. It also supports full local control, so automations can run without an internet connection.
Does it measure energy usage?
No. The Shelly 1 Gen3 does not have energy or power-consumption monitoring. If you need to track consumption, choose a Shelly PM model that includes power metering.
What can I use it for besides lights?
Thanks to its dry contacts and AC/DC power flexibility (up to 16A), owners use it for garage door openers, sump and pool pumps, irrigation, 3D printers and even to drive larger industrial relays. It can be wired in dry-contact mode to trigger almost anything.
Can I customize its behavior or firmware?
Yes. It supports on-device scripting (JavaScript) for custom logic and timers, and because it uses an ESP32-C3 chip, advanced users can flash custom ESPHome firmware for use with Home Assistant.








