Mozilla WebThings Gateway

Last reviewed Sep 13, 2026 · 755 words

Mozilla stopped funding WebThings Gateway in 2020, and the project moved to a community team at webthings.io that has kept it alive rather than growing it. That single fact sets expectations correctly: the gateway still installs in 20 minutes on a Raspberry Pi, still has the cleanest local-first smart-home UI I have used, and still has a fraction of the integrations of Home Assistant. With 2,645 stars against Home Assistant's tens of thousands, it is a considered choice for a specific kind of user, not a default.

The Web of Things idea is better than what won

Home Assistant integrates devices by writing a Python integration per vendor. WebThings takes the standards route: every device is a "web thing" with a JSON Thing Description, exposed over HTTP and WebSockets, following the W3C Web of Things specification. A DIY sensor on an ESP32 running the webthing-arduino library shows up in the gateway with no add-on at all, because it describes itself. The same goes for anything you write with webthing-python or webthing-node.

For people who build their own devices, that is the killer feature. There is no YAML, no MQTT topic naming convention to agree on, and the device's capabilities (a LightControl, a TemperatureSensor) map straight onto UI widgets. If you have ever spent an evening matching a Zigbee2MQTT payload to a Home Assistant entity, you will understand the appeal immediately.

Install on a Raspberry Pi in 20 minutes

The official route is a Raspberry Pi image: flash it, boot, browse to http://gateway.local, and register a free subdomain on webthings.io for remote access through a tunnel, or skip that and stay LAN-only. Docker works too, and host networking matters because device discovery uses mDNS and SSDP:

services:
  webthings:
    image: webthingsio/gateway:latest
    network_mode: host
    volumes:
      - ./data:/home/node/.webthings
    devices:
      - /dev/ttyACM0:/dev/ttyACM0
    restart: unless-stopped

The UI is on port 8080, HTTPS on 4443 once you enable it. The devices line passes a Zigbee or Z-Wave dongle through; without one, you are limited to Wi-Fi devices and web things. Everything, including add-ons and the SQLite database, lives in .webthings, which makes backup a directory copy. The 512 MB minimum in the catalogue is comfortable for a Pi 3 or better.

Integrations are where you feel the gap

Add-ons cover the common ground: Zigbee via a Conbee or similar dongle, Z-Wave, Philips Hue, TP-Link Kasa, Tasmota, HomeKit, Ikea, and a general Web Thing adapter. Past that, the list thins out fast. Cloud-connected vendors, cameras, energy monitors, and anything that arrived after 2021 are far more likely to have a Home Assistant integration than a WebThings add-on, and the pace at which new add-ons appear reflects a project maintained by volunteers in their evenings.

The workaround is Zigbee2MQTT plus an MQTT broker like Mosquitto, which broadens Zigbee coverage considerably, at the cost of exactly the MQTT plumbing WebThings was designed to avoid. Rules are the other half of the UI: a drag-and-drop rules engine that handles "if motion after sunset then light on for 10 minutes" without code, which is more than Home Assistant's automation editor offered until recently, and less than Node-RED offers now.

Who should still pick it

Three groups. Makers who build their own devices and want them to appear without glue code. Households with a small, stable set of Zigbee and Wi-Fi devices who value a UI a non-technical partner can operate. And people who want a smart home that is offline-first on principle, with no vendor account in the loop. If the device list is long, changes often, or includes anything exotic, openHAB or Home Assistant is the safer pick, and the Home Assistant first-month post covers the reasons in detail. The home automation category page compares the wider field.

What I'd do

Run WebThings Gateway if you are building your own sensors and want the cleanest local UI for them; a Pi 4, the official image, and an hour gets you there, and the .webthings directory is the only thing to back up. For a house full of commercial devices, install Home Assistant instead and, if the Web of Things idea appeals, expose your DIY devices to it over MQTT. Do not run both as peers; one hub owns the automations or none does.