The Two Kings of Wi-Fi Microcontrollers
For years, the ESP8266 was the go-to chip for cheap Wi-Fi connectivity in maker projects. Then Espressif released the ESP32 — a more powerful successor with dual cores, Bluetooth, more GPIO, and a host of new peripherals. Both chips remain popular today, so which one should you use in 2025?
Specifications Comparison
| Feature | ESP8266 | ESP32 |
|---|---|---|
| CPU | Single-core Xtensa L106, 80/160 MHz | Dual-core Xtensa LX6, up to 240 MHz |
| RAM | ~80 KB usable | ~320 KB SRAM |
| Flash | Typically 1–4 MB | Typically 4–16 MB |
| Wi-Fi | 802.11 b/g/n (2.4 GHz) | 802.11 b/g/n (2.4 GHz) |
| Bluetooth | None | BT Classic + BLE 4.2 |
| GPIO Pins | 17 | Up to 34 |
| ADC | 1 channel (10-bit) | 18 channels (12-bit) |
| DAC | None | 2 channels (8-bit) |
| Touch Pins | None | 10 capacitive pins |
| Deep Sleep Current | ~20 µA | ~10 µA |
| Price (module) | ~$1–2 | ~$2–4 |
Performance
The ESP32's dual-core architecture is a meaningful upgrade. You can run Wi-Fi and networking tasks on one core while your application logic runs uninterrupted on the other. The ESP8266 struggles with this — its single core means Wi-Fi activity can cause noticeable delays in your main loop. For any project requiring smooth, consistent timing alongside Wi-Fi, the ESP32 is the clear winner.
When the ESP8266 Still Makes Sense
Despite its age, the ESP8266 isn't obsolete. Here's when it's still a reasonable choice:
- Ultra-budget builds: At ~$1 per module in bulk, ESP8266 is hard to beat for high-volume, cost-sensitive products.
- Simple Wi-Fi tasks: Sending a sensor reading to a server every few minutes doesn't need dual cores.
- Legacy projects: Maintaining existing ESP8266 code is easier than porting to ESP32.
- Tiny form factor: The ESP-01 module is extremely small for space-constrained applications.
When You Should Choose the ESP32
- You need Bluetooth (classic or BLE) in addition to Wi-Fi
- Your project requires multiple analog inputs
- You need precise PWM or DAC output
- You want to use capacitive touch sensing
- You need more GPIO pins for complex wiring
- You're building something that needs real-time performance alongside networking
- You plan to use FreeRTOS or multi-threaded firmware
Power Consumption
Both chips support deep sleep, but the ESP32 actually draws less current in deep sleep (~10 µA vs ~20 µA for ESP8266). In active Wi-Fi transmission, both chips draw similar peak currents (~200–300 mA), so battery life for duty-cycled sensor nodes is comparable.
Community & Library Support
The ESP8266 has a mature, well-documented ecosystem built over many years. The ESP32 now has equal — or in many areas — superior support. Both chips work with Arduino IDE, MicroPython, and PlatformIO. For new projects, the ESP32's libraries are actively maintained and better supported by Espressif.
Verdict
For new projects in 2025, the ESP32 is almost always the better choice. The small price difference is more than justified by the significantly expanded feature set, better performance, and longer-term support from Espressif. Keep the ESP8266 for budget-constrained, high-volume production or legacy maintenance work.