| ESP32-C3 | ESP32-C6 | |
|---|---|---|
| CPU | Single-core RISC-V, up to 160 MHz | RISC-V up to 160 MHz + low-power RISC-V core |
| SRAM | 400 KB | 512 KB (plus a small low-power SRAM) |
| Wi-Fi | Wi-Fi 4 (802.11n), 2.4 GHz | Wi-Fi 6 (802.11ax), 2.4 GHz |
| Bluetooth | Bluetooth LE 5 | Bluetooth LE 5 |
| IEEE 802.15.4 (Thread, Zigbee) | No | Yes |
| GPIO (chip) | Up to 22 | Up to 30 |
| Arduino core | esp32 core 2.x and 3.x | esp32 core 3.x only |
| Typical board price in India | ₹200–350 (SuperMini) | ₹350–600 small boards · ₹900–1,400 DevKitC-1 |
The C3 is the cheap RISC-V workhorse. The C6 adds two radios’ worth of future-proofing: Wi-Fi 6 and an 802.15.4 radio for Thread and Zigbee. Whether that’s worth two to four times the price depends on your smart-home plans. Specs are from Espressif’s datasheets; prices are indicative.
What the C6 adds
- Thread and Zigbee. The C6 can join a Zigbee network or act as a Matter-over-Thread device — the direction big smart-home brands are moving. A C3 can only do Matter over Wi-Fi.
- Wi-Fi 6. Better behaviour on crowded networks, and Target Wake Time lets a battery device sleep between scheduled check-ins. Both need a Wi-Fi 6 router to benefit; on an older ISP router it behaves like Wi-Fi 4.
- A low-power core that can watch sensors while the main core sleeps.
- More pins and RAM.
Hub: ESP32-C6-DevKitC-1.
Why the C3 is still the default
- Price. A C3 SuperMini costs less than many sensors.
- Maturity. More examples, more boards, works with older 2.x core tutorials.
- Nothing in a typical project needs the C6’s extras — a sensor posting to MQTT or a web page works the same on both.
Hubs: ESP32-C3 SuperMini, XIAO ESP32C3.
Porting notes
- C6 needs esp32 core 3.x. Sketches written for 2.x that use the old LEDC (
ledcSetup/ledcAttachPin) or timer functions need the 3.x API. - Strapping pins differ: on the C6 avoid GPIO 4, 5, 8, 9 and 15; GPIO 12–13 are the native USB lines.
- Both are 3.3 V only.
Verdict
| You want… | Pick |
|---|---|
| Cheapest Wi-Fi + BLE node | C3 |
| A Zigbee or Thread / Matter device | C6 |
| Battery device on a Wi-Fi 6 router | C6 |
| Following older tutorials | C3 |
Comparing with the bigger chips? See ESP32-S3 vs ESP32-C3.