LocalBytes
LocalBytes Power Monitoring Smart Plug (ESPHome)
- Wi-Fi
Verified September 2026
A small UK reseller's plug that ships pre-flashed with ESPHome (or Tasmota), so it lands in HA with zero cloud dependency, zero vendor app, and OTA firmware you control end to end — nothing bricks if the seller vanishes tomorrow. That's the tinkerer's dream at under £15: no subscription, no forced updates, full local ownership. The tradeoff is a small, largely unknown brand rather than an established name — LocalBytes itself admits its factory power calibration "is not perfect," so budget time to calibrate against a known load. Best suited to privacy-conscious, offline-first households already running HA who don't mind setup friction in exchange for never phoning home.
In Home Assistant
| Control | Type | What it does |
|---|---|---|
| Switch | Toggle | Turn the plug on/off |
| Power / Voltage / Current / Energy | Sensor | Live and cumulative readings |
| Calibrate power/current/voltage | Button (x3) | Correct sensor drift against a known reference load |
As an ESPHome-native device it exposes a switch plus power, voltage, current and energy sensors directly, with no cloud round-trip — and uniquely for a plug at this price, it also exposes calibrate_power/current/voltage as HA-callable actions, so BL0937 drift can be corrected periodically against a known reference load (e.g. a kettle) rather than only at first setup. It's a community-maintained ESPHome package rather than an official vendor profile, so check the repo's recent activity before relying on it for anything critical.
Specs
- mcu
- ESP8266 (ESP8285N08)
- weight
- approx. 69g (per independent third-party review)
- firmware
- ESPHome (Tasmota variant available)
- max load
- 13A (UK variant; EU version rated 16A)
- plug type
- BS1363 Type G
- dimensions
- approx. 57 x 57 x 32mm (per independent third-party review; not published on LocalBytes' own spec sheet)
- hub required
- false
- voltage range
- AC 100-240V, 50Hz
- energy monitoring
- true
- power monitoring chip
- BL0937 + HLWBL — LocalBytes states factory calibration is approximate, not guaranteed-accurate out of the box