ESPHome 2026.1.0 optimizes memory usage on ESP32/ESP8266, adds Zigbee support on nRF52, WiFi roaming, and more

ESPHome 2026.1.0 open-source firmware has just been released with new features like automatic WiFi roaming and Zigbee support for Nordic Semi nRF52 targets, as well as memory optimization for ESP32/ESP8266 hardware, among many other changes.

Other notable changes include security updates with the project replacing API password authentication with API encryption and requiring SHA256 authentication for OTA updates, better support for non-ASCII configuration, and updates to LibreTiny platforms (BK72xx, RTL87xx, LN882x), which received thread-safe WiFi, atomics, and deep sleep support.

ESPHome developers used to advise users not to use ESP8266, not because it was not suitable for the task, but because the runtime heap on ESP8266 routinely dropped below 10k, and devices were unreliable. Since millions of ESP8266 devices were already deployed in homes, they decided to do something about it. The project was greatly helped thanks to increased support from the Open Home Foundation, which allows the project to have two full-time developers and a broader base of part-time contributors, and after months of work, the available heap increased from under 10k to over 30k in realistic configurations on ESP8266. The work also involved ESP32, ESP32-C3, ESP32-S2, and ESP32-S3 SoCs, as all moved to the ESP-IDF by default (instead of Arduino), delivering up to 40% smaller binaries and 2 to 3 times faster compile times. ESP32 RAM usage is also much lower thanks to a range of optimizations, and zero-copy API enables ESP32 camera streaming with about 10% lower latency.

Automatic WiFi roaming enables devices to switch to better access points after connecting, solving the problem of devices getting stuck on other access points (APs) after power outages or AP reboots. The web server now uses entity names directly in URLs with collision-free encoding, fixing issues that impacted non-ASCII (UTF-8) configurations, for example, Chinese characters not showing properly. Brotli compression was also enabled in the web server to save flash size.

With regards to Zigbee on  nRF52, the following highlights are provided:

• Binary sensor support – Expose GPIO states via Zigbee
• Sensor support – Expose ESPHome sensors via Zigbee’s Analog Input cluster with automatic unit mapping
• Switch support – Control ESPHome switches via Zigbee as binary output
• wipe_on_boot: once – Wipe network settings only on first boot, preserving connections after OTA updates
• Framework version support – Configure nRF-SDK version with experimental support for SDK 2.9.2 and 3.2.0

New hardware support includes:

• RD-03D mmWave Radar  (Ai-Thinker RD-03D 24GHz millimeter-wave radar module) to target up to 3 simultaneous targets
• BTHome MiThermometer to receive data from Xiaomi Mijia BLE sensors running PVVX firmware with BTHome v2 format
• Air Quality Index (AQI) Sensor support to compute Air Quality Index from particulate matter readings; it supports both EPA AQI (US) and CAQI (European) calculation methods.

Some of the changes will require modifications to your YAML configuration file. For instance, if you used the password API:

You’ll now need to switch to the encryption API:

If you still need Arduino components like heatpumpir or midea, you’ll need to set type: arduino in your configuration:

More details can be found in the changelog.

Thanks to Hedda for the tip.

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