Arduino Nano Boards Compared: Classic, Every, R4, ESP32, Matter, BLE and RP2040

The Arduino Nano name now covers several very different microcontroller architectures.

They share roughly the same compact 45 × 18 mm Nano form factor, but inside they range from an 8-bit ATmega328P to a 240 MHz ESP32-S3, a Cortex-M33 Matter/Thread platform, a 48 MHz RA4M1 with 5 V I/O, and an nRF52840 BLE board.

So choosing a Nano by physical size alone is a mistake.

In 2026, the most important Nano-family options are:

• Arduino Nano — classic ATmega328P;
• Arduino Nano Every — ATmega4809;
• Arduino Nano R4 — Renesas RA4M1;
• Arduino Nano ESP32 — ESP32-S3;
• Arduino Nano Matter — Silicon Labs MGM240S;
• Arduino Nano 33 BLE Rev2 — Nordic nRF52840;
• Arduino Nano RP2040 Connect — RP2040 + NINA-W102, now End of Life.

Nano 33 IoT and Nano 33 BLE Sense Rev2 also remain relevant, so we will position them where they fit rather than pretending the family is only seven boards.

Quick Recommendation

If you need…	Best-fit Nano architecture
Classic 5 V AVR compatibility	Nano or Nano Every
Modern 5 V control, CAN, DAC and RTC	Nano R4
Wi-Fi, BLE, ESP-NOW, MicroPython, ESP-IDF	Nano ESP32
Matter over Thread or Zigbee	Nano Matter
Bluetooth LE, low-power sensing and onboard IMU	Nano 33 BLE Rev2
RP2040 PIO and unusual timing/I/O work	Nano RP2040 Connect if you already own it
Wi-Fi with a SAMD21 main MCU	Nano 33 IoT
BLE + many onboard sensors + TinyML	Nano 33 BLE Sense Rev2

Nano Family Comparison Table

Board	Main MCU	CPU	Logic	RAM	Wireless	Key feature
Classic Nano	ATmega328P	8-bit AVR, 16 MHz	5 V	2 kB	None	Legacy compatibility
Nano Every	ATmega4809	8-bit megaAVR, up to 20 MHz	5 V	6 kB	None	Modernised AVR
Nano R4	RA4M1	Cortex-M4, 48 MHz	5 V	32 kB	None	CAN, DAC, RTC, USB-C, Qwiic
Nano ESP32	ESP32-S3	Dual LX7, up to 240 MHz	3.3 V	512 kB + 8 MB PSRAM	Wi-Fi + BLE	Native ESP32 platform
Nano Matter	MGM240S	Cortex-M33, 78 MHz	3.3 V	256 kB	Thread / 802.15.4 + BLE	Matter and Zigbee
Nano 33 BLE Rev2	nRF52840	Cortex-M4F, 64 MHz	3.3 V	256 kB	BLE + 802.15.4 hardware	BLE + 9-axis IMU
Nano RP2040 Connect	RP2040	Dual Cortex-M0+, 133 MHz	3.3 V	264 kB	Wi-Fi/BLE via NINA	PIO + 16 MB Flash

1. Classic Arduino Nano: Best for Legacy ATmega328P Projects

The original Nano remains the simplest member of the family.

It uses:

Its familiar pin functions are:

The biggest reason to choose it today is not performance. It is compatibility.

Use it when:

• you have an existing ATmega328P design;
• you need 5 V GPIO;
• a library directly targets AVR registers;
• 2 kB RAM is enough;
• you want the simplest possible AVR learning platform.

See our classic Arduino Nano pinout guide.

2. Nano Every: The Better AVR Nano

Nano Every keeps the familiar Nano shape and 5 V logic but upgrades the processor to the ATmega4809.

The ATmega4809 is a newer AVR architecture with:

• more memory;
• modern TCA/TCB timers;
• an event system;
• interrupt support on many more pins;
• UPDI programming;
• a separate SAMD11 USB bridge.

Nano Every Is Not Register-Compatible with ATmega328P

This is the main caveat.

Code written with:

does not simply transfer to ATmega4809.

Libraries using normal Arduino APIs are much easier to migrate.

Nano Every PWM Difference

The current Nano Every Arduino mapping supports normal PWM on:

D11 is not the same standard PWM pin it is on the classic Nano.

Another improvement is that A6/A7 are normal digital-capable GPIO on Nano Every.

See our Nano Every pinout guide.

3. Nano R4: The Strongest Choice for Modern 5 V Control

Nano R4 changes the architecture completely:

It keeps the electrical advantage many Nano users want — 5 V I/O — while adding peripherals that the AVR boards simply do not have.

Nano R4 Adds CAN, DAC, RTC and Native USB

Important features include:

• up to 14-bit ADC;
• 12-bit true DAC on A0;
• integrated op-amp;
• classic CAN controller;
• real-time clock;
• native USB-C;
• dedicated 3.3 V Qwiic bus;
• hardware floating-point support.

This makes Nano R4 particularly attractive for:

• automotive-style CAN projects;
• industrial control prototypes;
• 5 V sensors and actuators;
• mixed-signal applications;
• data logging with RTC;
• USB HID devices.

Nano R4 Does Not Have Built-In Wireless

Nano R4 is not a Wi-Fi or BLE board.

If networking is the primary requirement, Nano ESP32 or Nano Matter is usually a more natural starting point.

See our Nano R4 pinout guide.

4. Nano ESP32: The Most Powerful General-Purpose Wireless Nano

Nano ESP32 uses an ESP32-S3 inside the u-blox NORA-W106 module.

This is a dramatic step up in memory and processing capability compared with AVR and RA4M1 Nano boards.

Nano ESP32 Wireless

It includes:

• 2.4 GHz Wi-Fi;
• Bluetooth LE;
• ESP-NOW;
• Arduino Cloud support;
• MicroPython support;
• native ESP32-S3 USB/debugging.

Nano ESP32 Is the Native ESP32 Choice

Unlike Nano 33 IoT or RP2040 Connect, there is no separate application MCU plus ESP32 coprocessor.

Your sketch runs directly on the ESP32-S3:

This makes Nano ESP32 the cleanest Nano platform when your project is fundamentally an ESP32 project.

Nano ESP32 Trade-Offs

Its main limitations relative to Nano R4 are:

• 3.3 V rather than 5 V GPIO;
• no true voltage DAC;
• no built-in RTC comparable to RA4M1’s calendar RTC;
• analog behaviour is less attractive for precision work;
• Arduino pin numbering differs from raw ESP32 GPIO numbering.

See our Nano ESP32 pinout guide.

5. Nano Matter: Choose It for Thread, Matter and Zigbee

Nano Matter is based on Silicon Labs’ MGM240S:

Its defining feature is not CPU performance. It is the integrated IEEE 802.15.4 radio.

This enables:

• Thread;
• Matter over Thread;
• Zigbee in the current Arduino Silicon Labs core;
• Bluetooth LE 5.3;
• Bluetooth Mesh;
• low-power mesh networking.

Nano Matter Has No Wi-Fi Radio

This is important.

For Matter-over-Thread:

BLE is normally involved in commissioning, while operational Matter traffic then runs over Thread.

Nano Matter Analog Hardware

The MGM240S is also surprisingly capable as a general MCU:

• 12-bit ADC;
• up to four DAC channels;
• two SPI buses;
• two I²C buses;
• 22 exposed digital-capable I/O;
• flexible PWM;
• USB-C debugging through the onboard SAMD11.

See our Nano Matter pinout guide.

Nano Matter vs Nano ESP32

The simplest distinction is:

If your smart-home device is explicitly Matter-over-Thread, Nano Matter is architecturally the more direct solution.

6. Nano 33 BLE Rev2: BLE, Low Power and IMU

Nano 33 BLE Rev2 uses Nordic’s nRF52840:

It includes:

• Bluetooth LE;
• IEEE 802.15.4-capable radio hardware;
• BMI270 accelerometer/gyro;
• BMM150 magnetometer;
• native USB;
• flexible PWM;
• 12-bit ADC.

Nano 33 BLE Rev2 Is a Sensor/Wearable Platform

It fits naturally into projects such as:

• BLE wearables;
• motion sensing;
• orientation tracking;
• battery-powered sensors;
• wireless human-interface devices;
• TinyML motion classification.

It does not have Wi-Fi.

See our Nano 33 BLE Rev2 pinout guide.

What About Nano 33 BLE Sense Rev2?

The Sense model uses the same nRF52840 platform but adds a much richer sensor set:

• BMI270 + BMM150 motion/orientation;
• HS3003 temperature/humidity;
• LPS22HB pressure;
• APDS9960 colour/proximity/gesture;
• MP34DT06J microphone.

Choose the Sense Rev2 when your project is primarily about embedded sensing or TinyML.

See our Nano 33 BLE Sense Rev2 guide.

7. Nano RP2040 Connect: Still Unique for PIO, but End of Life

Nano RP2040 Connect combines:

with a separate ESP32-based NINA-W102 for Wi-Fi and Bluetooth.

RP2040 Connect’s Unique Strength Is PIO

The RP2040 provides:

PIO can implement unusual or timing-sensitive interfaces such as:

• extra UARTs;
• custom serial protocols;
• WS2812 output;
• precise pulse generation;
• quadrature decoding;
• specialised digital buses.

This remains its strongest architectural reason to exist.

But RP2040 Connect Is Now End of Life

Arduino currently marks Nano RP2040 Connect as End of Life.

That does not make existing boards useless, but it changes the recommendation for a new long-term design.

If you already own one, it remains a powerful board.

If you are starting a new project, compare its unique PIO advantage against current Nano ESP32, Nano R4 and other RP2040/RP2350 boards.

See our Nano RP2040 Connect pinout guide.

Where Does Nano 33 IoT Fit?

Nano 33 IoT is still a useful board based on:

Its architecture is:

This is conceptually similar to RP2040 Connect’s two-processor wireless architecture.

Nano 33 IoT Still Makes Sense When…

• you already have SAMD21 software;
• you need a true 10-bit DAC on A0;
• native SAMD21 USB matters;
• you want WiFiNINA compatibility;
• you have an existing Nano 33 IoT design.

For a greenfield high-performance Wi-Fi design, Nano ESP32 generally gives much more processing and memory headroom.

See our Nano 33 IoT pinout guide.

5 V vs 3.3 V: The First Decision

5 V Nano boards	3.3 V Nano boards
Classic Nano	Nano ESP32
Nano Every	Nano Matter
Nano R4	Nano 33 BLE Rev2
	Nano 33 BLE Sense Rev2
	Nano 33 IoT
	Nano RP2040 Connect

If your existing hardware contains many 5 V sensors, relay boards and shields, this single distinction can eliminate half the Nano family immediately.

Which Nano Has the Most Processing Power?

For raw application performance and memory headroom:

is in a different class from the AVR boards.

But raw CPU speed is not the only reason to choose a microcontroller.

Nano R4 has stronger 5 V mixed-signal/control features, Nano Matter has native 802.15.4, and Nano 33 BLE has a particularly strong low-power BLE ecosystem.

Which Nano Has the Best Analog Features?

For mixed-signal hardware, Nano R4 is particularly strong:

Nano Matter also has strong analog hardware, with multiple DAC-capable channels at 3.3 V.

Nano ESP32 has capable ADC hardware but no true DAC and is generally less attractive when analog precision is the primary requirement.

Which Nano Is Best for CAN?

Nano R4 has a built-in classic CAN controller with fixed board mapping:

An external CAN transceiver is still required.

Nano ESP32’s ESP32-S3 also has a TWAI/classic-CAN controller, but the board does not provide the same straightforward dedicated Nano CAN pin identity.

For a conventional embedded CAN node, Nano R4 is the more direct Arduino-style hardware layout.

Which Nano Is Best for Wi-Fi?

There are three important wireless architectures:

Nano ESP32 avoids the coprocessor layer and has dramatically more RAM and CPU performance.

Which Nano Is Best for Matter?

For Matter-over-Thread:

is the purpose-built choice because the MGM240S includes IEEE 802.15.4 and the Arduino Silicon Labs platform supports Matter, OpenThread and Zigbee.

Nano ESP32 cannot provide native Matter-over-Thread by itself because ESP32-S3 lacks an 802.15.4 radio.

Which Nano Is Best for Bluetooth?

If Bluetooth is just one of several features, Nano ESP32 is convenient.

If the project is primarily a low-power BLE sensor or wearable, Nano 33 BLE Rev2’s nRF52840 architecture is a particularly natural fit.

If BLE is mainly being used to commission Matter/Thread devices, Nano Matter is the intended architecture.

Which Nano Is Best for TinyML?

There are several strong choices:

• Nano 33 BLE Sense Rev2 — many onboard sensors, ideal for sensor/audio TinyML;
• Nano ESP32 — large PSRAM and fast ESP32-S3 for larger models and networking;
• Nano 33 BLE Rev2 — good motion-focused TinyML with onboard IMU;
• Nano RP2040 Connect — capable RP2040 plus IMU/microphone, but EOL.

Which Nano Is Best for Existing AVR Code?

If your project contains direct AVR register manipulation, use:

if possible.

Nano Every remains an AVR platform but uses a different megaAVR 0-series peripheral architecture, so low-level ATmega328P code may still need rewriting.

USB Differences

Board	USB architecture
Classic Nano	FT232RL USB-to-serial bridge
Nano Every	SAMD11 USB bridge to ATmega4809
Nano R4	Native RA4M1 USB-C
Nano ESP32	Native ESP32-S3 USB-C
Nano Matter	USB-C through onboard debugger/bridge
Nano 33 BLE Rev2	Native nRF52840 USB
Nano RP2040 Connect	Native RP2040 USB

If your project needs native USB HID, this distinction matters.

Memory Comparison

Board	Flash	RAM
Classic Nano	32 kB	2 kB
Nano Every	48 kB	6 kB
Nano R4	256 kB	32 kB
Nano ESP32	16 MB external	512 kB + 8 MB PSRAM
Nano Matter	1536 kB	256 kB
Nano 33 BLE Rev2	1 MB	256 kB
Nano RP2040 Connect	16 MB external	264 kB

Decision Tree

Final Comparison

There is no single Nano board that replaces every other Nano.

The family now divides into distinct architectures:

For most new projects, choose based on the peripheral architecture before comparing CPU speed.

If the project needs 5 V logic, CAN and good analog hardware, Nano R4 is a very different answer from Nano ESP32.

If the project is Wi-Fi-heavy, Nano ESP32’s large PSRAM and native ESP32 architecture are more important than Nano R4’s better analog peripherals.

If the project is a Matter-over-Thread accessory, Nano Matter’s 802.15.4 radio matters more than raw clock speed.

And if the project is a battery BLE wearable, the nRF52840-based Nano 33 BLE Rev2 remains a much more natural architecture than simply choosing the fastest CPU.