Shelly 1 Mini Gen3 Review: A Cheap, Tiny Wi-Fi Relay for DIY Automation
One of the smallest smart relays around, with dry contacts, local control and a web UI, let down only by a confusing wiring diagram.
The Shelly 1 Mini Gen3 is a tiny, cheap Wi-Fi smart relay that hides behind an existing switch or inside an appliance to make almost any circuit smart, with no hub required. It rates 8A, needs a neutral wire, and offers both dry-contact and wet-contact modes, making it a favorite for garage doors, sprinklers, fireplaces, shutters and low-voltage projects. It runs locally for instant, lag-free response (its own web interface means you do not even need the app or cloud), integrates with Alexa, Google Home, SmartThings and Home Assistant, and is deeply programmable (timers, actions, even HTTP control from an ESP32). The big catch, repeated across reviews, is that the included wiring diagram is misleading (the I/O terminals are the relay switch, not power output), so first-time installers often need a YouTube guide. It is Wi-Fi-only with no Matter, Zigbee, HomeKit or energy monitoring; the Gen4 adds those radios.
- Budget DIY automation
- Home Assistant users
- Garage doors, sprinklers and shutters
- Tight switch boxes
Pros
- Extremely small and cheap; fits behind a switch, outlet or inside an appliance
- Dry and wet contacts for garage doors, sprinklers, fireplaces, shutters and more
- Full local control with instant, lag-free response and its own web interface
- No hub required; works with Alexa, Google, SmartThings and Home Assistant
- Highly programmable (timers, actions, HTTP control from an ESP32); OTA updates
- Wi-Fi range-extender and Bluetooth gateway roles; preserves the manual switch
Cons
- Included wiring diagram is misleading (I/O are the relay switch, not power output)
- Overwhelming instructions and unclear app pairing; expect to consult online guides
- Requires a neutral wire and basic electrical know-how
- Wi-Fi only: no Matter, Zigbee or Apple HomeKit (the Gen4 adds these)
- No energy monitoring and no DIN-rail mount
- Rated 8A, so for lighter loads
Who is the Shelly 1 Mini Gen3 for?
This is a very small, very affordable single-channel smart relay for DIYers who want to add smart control to existing wiring without a hub. It is small enough to fit behind a switch or outlet or even inside an appliance, rates 8A at 110-240V AC (and up to 5A at 30V DC), requires a neutral wire, and supports both dry-contact and wet-contact modes. It connects over 2.4GHz Wi-Fi (with Bluetooth for pairing and a Wi-Fi range-extender/gateway role) and works with Amazon Alexa, Google Home, Samsung SmartThings and Home Assistant, with OTA updates and full local control. Note this Gen3 is Wi-Fi only: there is no Matter, Zigbee or Apple HomeKit (the Gen4 adds those). It best suits budget-minded automation builders, Home Assistant users, makers who want to drive it from an ESP32 or scripts, and projects like garage door openers, sprinkler/irrigation control, gas fireplaces, rolling shutters and remote generator start.
What buyers love
Owners rave about the value and size: at around the price of a fancy coffee, it is one of the smallest relays available, installs in roughly ten minutes, and disappears inside a junction box. The dry contacts make it a do-anything device, and reviewers list a huge range of solved problems: momentary triggers for garage doors, latched control for sprinklers, switching a low-voltage gas fireplace that had no neutral for a normal smart switch, controlling rolling shutters, starting a generator remotely, and bypassing a wall switch to power a camera while still controlling a light. The local control is a major draw: response is instant with no lag, and the device exposes its own web interface (via AP mode) so you can configure timers and actions without ever using the app or cloud. It integrates cleanly with Home Assistant, supports firmware updates over the air, and is very programmable, with makers driving it over HTTP from an ESP32 and even having two units talk to each other without Wi-Fi. Many owners run dozens of Shelly modules and call this their favorite for embedding control anywhere.
What to know before you buy
The single most common complaint is the wiring documentation. The diagram included with the device is misleading: the I (input) and O terminals are the relay switch contacts, not a neutral or power output as the schematic seems to imply, so the standard wiring is power to L and N, a jumper from L to I, and the load to O and N. Multiple owners thought they had a defective unit until they found the correct diagram on YouTube or in another product's manual. The printed instructions are generally overwhelming and light on the specific wiring plan you need, and app pairing also lacks clear instructions, so first-timers often search online to get it connected (once working, it is reliable). It requires a neutral wire and basic electrical competence. Feature-wise, this Gen3 has no energy monitoring, no DIN-rail mount, and is Wi-Fi only with no Matter, Zigbee or HomeKit support. If you want those radios, the Gen4 is the one to get.
Is the Shelly 1 Mini Gen3 worth it?
Yes, for DIY automation on a budget it is excellent value: it is tiny, cheap, reliable once wired correctly, runs locally with no lag, and its dry contacts plus web UI make it a versatile building block for lights, garage doors, sprinklers, fireplaces and more. The one thing to be ready for is the confusing wiring diagram, so pull up a known-good guide before you start. Choose this Gen3 if you only need Wi-Fi and want the lowest price; step up to the Mini Gen4 if you want Matter, Zigbee or Apple HomeKit. For Home Assistant users and makers who do not mind a little wiring research, it is one of the best-value smart relays you can buy.
Frequently asked questions
Why won't it work when I follow the included wiring diagram?
The included diagram is misleading. The I and O terminals are the relay switch contacts, not a neutral or power output. The standard wiring is power to L and N, a jumper from L to I, and the load to O and N. Many owners only got it working after finding the correct diagram online.
Does it need a hub or the cloud?
No. It connects directly over 2.4GHz Wi-Fi with no hub, and it supports full local control. It even exposes its own web interface (via AP mode), so you can configure timers and actions without using the app or any cloud service.
Which platforms does it work with?
It works with Amazon Alexa, Google Home, Samsung SmartThings and Home Assistant. This Gen3 is Wi-Fi only and does not support Matter, Zigbee or Apple HomeKit; the Shelly 1 Mini Gen4 adds those.
What can I use the dry contacts for?
Lots of low-voltage and switching jobs: momentary triggers for garage doors, latched control for sprinklers or irrigation, switching a low-voltage gas fireplace, controlling rolling shutters, or remotely starting a generator. You can also apply power on the output terminals to control lights directly.
Does it measure energy usage?
No. The Shelly 1 Mini Gen3 does not include energy or power-consumption monitoring. If you need power metering, choose a Shelly PM model instead.








