Arduino Nano ESP32 vs Seeed XIAO ESP32-S3: Size, GPIO, Battery and USB

The Arduino Nano ESP32 and Seeed Studio XIAO ESP32-S3 are both compact ESP32-S3 development boards.

They share the same fundamental processor family:

• dual-core Xtensa LX7 CPU;
• clock speed up to 240 MHz;
• 2.4 GHz Wi-Fi;
• Bluetooth Low Energy;
• native USB;
• 12-bit ADC;
• LEDC PWM;
• ESP-NOW;
• Arduino and MicroPython support.

But they are designed around very different physical priorities.

So the real choice is not processor performance. It is whether you need the Nano ecosystem and extra I/O or the XIAO’s much smaller footprint and built-in battery features.

Quick Comparison

Feature	Arduino Nano ESP32	Seeed XIAO ESP32-S3
MCU	ESP32-S3 inside NORA-W106	ESP32-S3R8
CPU	Dual-core Xtensa LX7, up to 240 MHz	Dual-core Xtensa LX7, up to 240 MHz
Logic voltage	3.3 V	3.3 V
Flash	16 MB	8 MB standard XIAO
PSRAM	8 MB	8 MB
Wi-Fi	2.4 GHz	2.4 GHz
Bluetooth	BLE	BLE 5.0 / Bluetooth Mesh
Main exposed GPIO	About 21 user signal positions	11 main GPIO on standard XIAO
Analog inputs	8 Nano-labelled analog inputs	9 ADC-capable main header pins
USB	USB-C	USB-C
Battery charging	No dedicated onboard Li-ion charger	Yes
Battery input	External regulator/power design required	3.7 V lithium battery input
VIN	6-21 V	No equivalent wide-range VIN
Antenna	Integrated module antenna	U.FL external antenna connector
Dimensions	Nano format, roughly 45 × 18 mm class	21 × 17.8 mm
Best fit	Nano carriers, larger I/O count, general ESP32 development	Wearables, battery nodes, very compact products

Same ESP32-S3, Similar Raw CPU Performance

Both boards use the ESP32-S3 family, so the raw processor capability is broadly similar.

If the same sketch runs at the same CPU frequency, the CPU itself is not the main reason to choose one board over the other.

Nano ESP32 Has Twice the Flash

Arduino Nano ESP32 provides:

The standard XIAO ESP32-S3 provides:

So both have the same PSRAM capacity, but Nano ESP32 has twice the Flash.

When Extra Flash Matters

The additional Nano ESP32 Flash is useful for:

• larger OTA partitions;
• LittleFS or SPIFFS filesystems;
• web assets;
• MicroPython files;
• larger firmware builds;
• stored configuration/data.

For many normal sensor nodes, 8 MB is already plenty. For large web applications or multiple OTA partitions, 16 MB gives more flexibility.

Both Have 8 MB PSRAM

PSRAM is one reason both boards are much more capable than early ESP32 development boards.

8 MB PSRAM is useful for:

• large graphics buffers;
• audio buffers;
• large JSON documents;
• ML inference;
• camera frames;
• MicroPython heaps.

So RAM capacity does not strongly separate the standard Nano ESP32 from the standard XIAO ESP32-S3.

Size: XIAO Is Dramatically Smaller

Seeed specifies the XIAO ESP32-S3 at:

That makes it roughly half the length of a traditional Arduino Nano.

This difference is enormous in:

• wearables;
• small remote sensors;
• handheld devices;
• RC models;
• small enclosures;
• embedded products where every millimetre matters.

Nano ESP32 Is Still Compact

Nano ESP32 is not large by normal development-board standards.

It retains the familiar narrow Nano footprint, which is easy to:

• plug into breadboards;
• socket into carrier boards;
• replace in existing Nano-based hardware;
• mount in small enclosures.

But XIAO is in a different physical size class.

GPIO Count: Nano ESP32 Gives You More External Signals

Nano ESP32 exposes the traditional Nano-style set:

with around 21 usable external signal positions depending on how shared functions are counted.

The standard XIAO ESP32-S3 exposes:

for 11 primary header GPIO.

XIAO ESP32-S3 Main Pin Map

XIAO pin	ESP32-S3 GPIO	Default function
D0	GPIO1	GPIO, ADC
D1	GPIO2	GPIO, ADC
D2	GPIO3	GPIO, ADC
D3	GPIO4	GPIO, ADC
D4	GPIO5	SDA, GPIO, ADC
D5	GPIO6	SCL, GPIO, ADC
D6	GPIO43	UART TX
D7	GPIO44	UART RX
D8	GPIO7	SPI SCK, ADC
D9	GPIO8	SPI MISO, ADC
D10	GPIO9	SPI MOSI, ADC

This is enough for many compact IoT designs, but it can become restrictive once a project adds:

• display;
• SD card;
• multiple buttons;
• several chip-select lines;
• UART peripherals;
• many sensors.

Nano ESP32 Is Better When I/O Count Matters

Nano ESP32’s larger header gives you more freedom to combine:

• SPI display;
• I²C sensors;
• UART device;
• buttons;
• interrupt inputs;
• extra PWM outputs.

That additional pin budget often matters more than a few millimetres of board size.

XIAO Has Excellent Analog Density

Seeed documents:

on the standard XIAO ESP32-S3 main header.

That is impressive for such a tiny board.

The analog-capable pins include GPIO1 through GPIO9 with the appropriate board mapping.

Both Use 12-Bit ESP32-S3 ADC Hardware

Because both use ESP32-S3, neither is a precision analog platform by default.

For accurate measurements:

• calibrate;
• average samples;
• use ADC1 where practical;
• consider an external ADC for instrumentation-grade measurements.

No True DAC on Either Board

ESP32-S3 has no traditional internal voltage DAC.

So both Nano ESP32 and XIAO ESP32-S3 require:

• PWM plus filtering;
• external DAC;
• I²S DAC/codec;

for true analog output.

USB-C on Both Boards

Both use USB-C for:

• programming;
• power;
• serial communication;
• native USB functions.

This is a major usability advantage over older Micro-USB ESP32 boards.

Native USB and USB/JTAG

Both benefit from ESP32-S3 native USB capability.

You can use the USB interface for:

• USB serial;
• USB HID;
• CDC;
• USB/JTAG debugging;
• custom supported USB device classes.

The basic processor capability is therefore similar.

Battery Support Is the XIAO’s Biggest Hardware Advantage

XIAO ESP32-S3 includes onboard lithium-battery power management.

Seeed specifies a battery input around:

and the board can charge the battery through USB-C.

This is extremely useful for:

• wearables;
• portable sensors;
• asset trackers;
• handheld controllers;
• battery-powered BLE devices.

Standard XIAO ESP32-S3 Charging Current

Seeed documents approximately:

for the standard XIAO ESP32-S3.

This is intentionally modest and appropriate for small lithium cells.

Nano ESP32 Does Not Have a Dedicated Li-Ion Charger

Nano ESP32 can absolutely run from batteries, but you need external battery-management hardware such as:

• Li-ion charger;
• boost/buck regulator;
• protection circuit;
• battery connector.

For a portable project, that means extra PCB area and components.

Nano ESP32 Wins on Wide VIN Input

Arduino specifies:

for Nano ESP32.

This is convenient for embedded systems powered from:

• 9 V;
• 12 V;
• industrial/automotive-style rails within the specified range.

XIAO ESP32-S3 is designed around:

rather than a wide external VIN range.

Different Power Philosophies

The boards therefore target different power architectures.

XIAO Deep Sleep

Seeed documents a typical standard-board deep-sleep figure around:

when powered around 3.8 V under the documented test conditions.

That makes XIAO especially interesting for long-duty-cycle battery projects.

Real battery life still depends on:

• Wi-Fi wake time;
• BLE advertising;
• sensor consumption;
• regulator efficiency;
• LED state;
• battery self-discharge.

Nano ESP32 Low-Power Figures Need Context

Arduino quotes very low ESP32-S3 chip-level sleep currents, but also notes that total board current is higher because other components remain on the board.

So do not compare:

directly against:

without matching test conditions.

XIAO Has an External-Antenna Connector

The standard XIAO ESP32-S3 includes a:

This is a major advantage for:

• metal enclosures;
• remote antennas;
• wearables where PCB orientation is poor;
• installations requiring better antenna placement.

Seeed reports over 100 m range in appropriate conditions with a suitable U.FL antenna, although real range depends heavily on environment and antenna design.

Nano ESP32 Uses an Integrated Antenna

Nano ESP32’s NORA-W106 module uses its integrated antenna.

That simplifies:

• certification;
• assembly;
• carrier-board design;
• compact installations.

But you cannot simply relocate the antenna with a U.FL cable.

UART Mapping

XIAO ESP32-S3 defaults to:

Nano ESP32 presents the more traditional Nano:

Both ultimately use the ESP32-S3 UART hardware and GPIO matrix, so remapping is possible.

I²C Mapping

XIAO defaults to:

Nano ESP32 defaults to:

Again, ESP32-S3 can route I²C through the GPIO matrix if your project needs alternate pins.

SPI Mapping

XIAO defaults to:

Nano ESP32 uses the familiar Nano-style:

If you move a sketch between boards, SPI pin definitions need attention.

Pin Naming Is Cleaner on XIAO

XIAO’s Arduino labels map clearly to defined ESP32 GPIOs.

Nano ESP32 supports an Arduino pin-numbering layer over raw ESP32 GPIO numbers.

On Nano ESP32, using symbolic names such as:

is much safer than using bare integers.

XIAO Has User and Charge LEDs

The standard board includes:

• user LED;
• charge-status LED;
• BOOT button;
• RESET button.

The user LED is associated with:

and is active-low in common examples.

Nano ESP32 Integrates More Naturally with Arduino Accessories

The traditional Nano footprint means Nano ESP32 fits:

• Nano carrier boards;
• Nano screw-terminal adapters;
• Nano prototype boards;
• existing Nano sockets;
• many third-party accessories.

XIAO has its own ecosystem of tiny expansion boards, but it is not mechanically compatible with Nano hardware.

XIAO Ecosystem Is Very Strong for Tiny Modules

Seeed has built a large XIAO accessory ecosystem around:

• small displays;
• battery boards;
• sensors;
• LoRa extensions;
• camera/Sense variants;
• compact base boards.

For very small devices, that ecosystem can be more appropriate than adapting Nano hardware.

XIAO ESP32-S3 Sense

If you need camera/audio capability, Seeed also offers the XIAO ESP32-S3 Sense.

The current Sense platform adds:

• camera support;
• digital microphone;
• microSD support through its expansion board.

This makes the XIAO family particularly strong for compact vision and voice projects.

XIAO ESP32-S3 Plus

Seeed also offers a Plus variant with:

which closes some of the gaps to Nano ESP32.

But the standard XIAO ESP32-S3 remains the most relevant direct comparison because its main advantage is extreme compactness.

MicroPython

Both platforms can run MicroPython.

Nano ESP32 has official Arduino MicroPython documentation and a generous 16 MB Flash configuration.

XIAO ESP32-S3 is also widely used with MicroPython and has enough 8 MB PSRAM to support substantial applications.

Which Board Is Better for Wearables?

XIAO ESP32-S3 has the advantage because it combines:

• 21 × 17.8 mm size;
• battery charging;
• U.FL antenna;
• low-power modes;
• enough GPIO for common wearable sensors.

Nano ESP32 can certainly be used in wearables, but it requires more board area and external battery-management hardware.

Which Board Is Better for a Large Sensor Node?

Nano ESP32 often wins when the project needs:

• many I/O lines;
• several SPI/I²C devices;
• more chip-select pins;
• multiple buttons;
• Nano carrier-board hardware.

Which Board Is Better for a 12 V Project?

Nano ESP32.

Its:

means it can accept a typical 12 V project supply directly within the documented limits.

XIAO requires an external regulator to convert 12 V to an appropriate board input.

Which Board Is Better for Battery Power?

XIAO ESP32-S3.

The integrated charger and battery pads eliminate several external components.

For a rechargeable portable project, this is one of the clearest differences between the boards.

Which Board Is Better for RF Flexibility?

XIAO ESP32-S3 wins when you need an external antenna.

Nano ESP32 wins when you want an integrated certified module antenna and do not want to manage external RF hardware.

Which Board Is Better for GPIO-Heavy Projects?

Nano ESP32 generally wins because it exposes significantly more user pins.

If the XIAO project needs:

• large parallel bus;
• many relays;
• large keypad matrix;
• several UARTs;
• many chip-select lines;

the 11 primary XIAO pins can become restrictive.

Which Board Is Better for a Finished Product?

It depends on the mechanical design.

Choose XIAO when:

• size is critical;
• the device runs from a small Li-ion cell;
• 11 GPIO are enough;
• external antenna capability helps.

Choose Nano ESP32 when:

• the product already uses Nano carriers;
• you need more I/O;
• wide VIN simplifies system power;
• 16 MB Flash is useful;
• the slightly larger board is acceptable.

Decision Table

Requirement	Better fit
Smallest physical size	XIAO ESP32-S3
Built-in Li-ion charging	XIAO ESP32-S3
Wearable project	XIAO ESP32-S3
External U.FL antenna	XIAO ESP32-S3
Lowest complete-board deep sleep focus	XIAO ESP32-S3
More exposed GPIO	Nano ESP32
16 MB Flash	Nano ESP32
8 MB PSRAM	Both
6-21 V VIN	Nano ESP32
Nano carrier compatibility	Nano ESP32
USB-C	Both
Wi-Fi/BLE/ESP-NOW	Both

Quick Reference

Final Thoughts

Nano ESP32 and XIAO ESP32-S3 offer very similar processor performance because both are ESP32-S3 boards.

The deciding factors are board design.

Choose Arduino Nano ESP32 when you want:

• more I/O;
• 16 MB Flash;
• Nano accessory compatibility;
• wide 6-21 V VIN;
• a familiar breadboard/carrier format.

Choose Seeed XIAO ESP32-S3 when you want:

• the smallest possible ESP32-S3 board;
• built-in lithium-battery charging;
• wearable-friendly power design;
• U.FL external antenna support;
• a compact 21 × 17.8 mm footprint.

The simplest decision rule is:

For the Arduino board pinout, see our Nano ESP32 pinout guide.