Seeed Studio XIAO ESP32S3
The Seeed Studio XIAO ESP32S3 packs the full ESP32-S3 feature set — dual-core LX7, 8MB PSRAM, WiFi, BLE 5.0 — into a 21x17.5mm package with USB-C and battery charging. It is the smallest ESP32-S3 board available, ideal for space-constrained wearables, compact sensors, and projects where every millimeter matters.
Best for ultra-compact projects needing ESP32-S3 power, skip if you need more than 11 GPIO pins.
Where to Buy
Pros
- 21x17.5mm footprint — smallest ESP32-S3 board available
- Full ESP32-S3 specs: dual-core LX7 at 240MHz, 8MB flash, 8MB PSRAM
- Built-in LiPo battery charging circuit for portable projects
- USB-C with OTG support — modern and reversible connector
Cons
- Only 11 GPIO pins exposed — severely limits multi-peripheral projects
- No breadboard-friendly pin header without a breakout board
- Camera connector only on the Sense variant (sold separately)
Form Factor
At 21x17.5mm, the XIAO ESP32S3 is roughly the size of a US postage stamp. Seeed's XIAO form factor has castellated pads on the edges rather than through-hole pins, making it suitable for surface-mount soldering onto a carrier PCB or use with the XIAO expansion board.
The compact size comes at a cost: only 11 GPIO pins are accessible. This is enough for 1-2 SPI devices, an I2C bus, and a couple of digital I/O lines, but multi-sensor projects will quickly exhaust available pins. The ESP32-S3-DevKitC exposes 45 GPIO pins from the same chip.
Full S3 Performance in a Tiny Package
Despite the small footprint, the XIAO ESP32S3 runs the same dual-core Xtensa LX7 at 240MHz with 8MB flash and 8MB PSRAM as the full DevKitC. Processing performance, memory capacity, and wireless capabilities are identical to Espressif's reference design.
This means the XIAO can run the same firmware, the same ML models, and the same WiFi/BLE stacks as the DevKitC. The only real difference is pin availability and the physical form factor. For projects where you write firmware on the DevKitC and deploy on the XIAO, the code port is trivial — just remap the GPIO assignments.
Battery Integration
The built-in LiPo charging circuit accepts a single-cell lithium battery and charges via the USB-C port. Deep sleep current is approximately 14uA — higher than the ESP32-S3-DevKitC's 7uA due to the additional charging circuitry and power management components on the board.
For battery-powered applications, the 14uA idle draw is acceptable for devices that wake every few minutes to transmit data. For ultra-low-power sensors that need to last years on a coin cell, the ESP32-C3 at 5uA deep sleep is a better match — but it lacks the S3's dual-core power and PSRAM.
Full Specifications
Processor
| Specification | Value |
|---|---|
| Architecture | Xtensa LX7 |
| CPU Cores | 2 |
| Clock Speed | 240 MHz |
Memory
| Specification | Value |
|---|---|
| Flash | 8 MB |
| SRAM | 512 KB |
| PSRAM | 8 MB |
Connectivity
| Specification | Value |
|---|---|
| WiFi | 802.11 b/g/n |
| Bluetooth | 5.0 |
I/O & Interfaces
| Specification | Value |
|---|---|
| GPIO Pins | 11 |
| ADC Channels | 9 |
| SPI | 1 |
| I2C | 1 |
| UART | 1 |
| USB | USB-C (OTG) |
| Camera Connector | OV2640 connector (Sense variant) |
Power
| Specification | Value |
|---|---|
| Input Voltage | 5 V |
| Deep Sleep Current | 14 uA |
| Battery Charging | Yes |
Physical
| Specification | Value |
|---|---|
| Dimensions | 21 x 17.5 mm |
| Form Factor | XIAO (ultra-compact) |
Who Should Buy This
21x17.5mm is small enough to embed in a tracker housing. Battery charging built in. UART for GPS module, WiFi for data upload. 8MB PSRAM for route logging.
11 GPIO pins run out fast. No standard breadboard spacing. The ESP32-S3-DevKitC has 45 GPIOs and fits a breadboard directly.
Better alternative: ESP32-S3-DevKitC-1
The XIAO ESP32S3 Sense variant includes an OV2640 camera and microphone in the tiny package. If you need the camera, buy the Sense version specifically.
Small enough for a wristband housing. Battery charging circuit handles LiPo management. BLE 5.0 for phone connectivity. 8MB PSRAM buffers sensor data between syncs.
Frequently Asked Questions
How does the XIAO ESP32S3 compare to the DevKitC?
Same chip, same performance. The XIAO is 3x smaller (21x17.5mm vs 69x25.4mm) with battery charging built in, but exposes only 11 GPIO pins versus the DevKitC's 45. Choose the XIAO for compactness, the DevKitC for prototyping flexibility.
Can the XIAO ESP32S3 use a camera?
The standard XIAO ESP32S3 does not have a camera connector. The XIAO ESP32S3 Sense variant includes an OV2640 camera module and digital microphone. It is a separate product you need to purchase specifically.
Does the XIAO fit on a breadboard?
Not directly — it uses castellated pads, not standard 0.1 inch through-hole pins. Seeed sells a XIAO expansion board that adds breadboard-compatible headers, Grove connectors, and a small OLED display.
What battery does the XIAO ESP32S3 use?
A single-cell 3.7V LiPo or Li-Ion battery. The built-in charging circuit handles charging via USB-C. There is a battery connector pad on the bottom of the board. No battery is included with the board.
Is 11 GPIO pins enough for my project?
It depends. With I2C (1 bus, up to 127 devices) and SPI (1 bus, multiple chip selects), you can connect several peripherals. But if you need more than 3-4 independent digital I/O lines beyond SPI/I2C, you will likely run short.