Espressif’s ESP32 line has expanded far beyond the original dual-core Wi-Fi/Bluetooth chip that first popularised low-cost IoT. What started as a chip ubiquitous in smart home technology has grown to be something so much more than that, building out an entire ecosystem of small, low-cost microcontrollers that anyone can use to do, well, basically anything. Today, the name covers several unrelated silicon “series” that share the same ESP-IDF toolchain but differ in CPU architecture, wireless mix, memory size, and peripheral blocks. We’ll break down the major differences between all of them, as there’s a lot to know if you’re looking to invest in one of these to ensure you make the right choice.