Arduino Nano 33 BLE vs Nano ESP32: nRF52840 or ESP32-S3?

The Arduino Nano 33 BLE Rev2 and Arduino Nano ESP32 are both compact 3.3 V wireless boards in Arduino’s Nano family, but they are built for very different jobs.

Nano 33 BLE Rev2 is based on Nordic Semiconductor’s nRF52840:

Nano ESP32 is based on Espressif’s ESP32-S3 inside the u-blox NORA-W106 module:

The practical choice is usually simple:

Quick Comparison

Feature	Nano 33 BLE Rev2	Nano ESP32
Main MCU	Nordic nRF52840 in NINA-B306	ESP32-S3 in NORA-W106-10B
CPU	Arm Cortex-M4F	Dual-core Xtensa LX7
Clock	64 MHz	Up to 240 MHz
Flash	1 MB	16 MB external
RAM	256 kB	512 kB internal + 8 MB PSRAM
Logic voltage	3.3 V	3.3 V
Wi-Fi	No	2.4 GHz Wi-Fi 4
Bluetooth	Bluetooth 5-class BLE	Bluetooth LE 5.0
802.15.4 hardware	Yes in nRF52840	No
Thread/Zigbee silicon capability	Yes	No native 802.15.4 radio
ESP-NOW	No	Yes
ADC	12-bit, 8 channels	12-bit SAR ADC
True DAC	No	No
Onboard IMU	BMI270 + BMM150, 9-axis	No
USB	Native nRF52840 USB, Micro-USB	Native ESP32-S3 USB, USB-C
Debugging	SWD pads	Built-in USB/JTAG
MicroPython	Supported	Supported
Best fit	BLE sensors, wearables, motion, low-power nodes	Wi-Fi IoT, web, MQTT, ESP-NOW, memory-heavy applications

Use the Rev2 Board for a Current Comparison

The original Arduino Nano 33 BLE is now listed by Arduino as End of Life.

The current product is:

The main processor remains the nRF52840, but the IMU changed from the original LSM9DS1 arrangement to:

which together provide 9-axis motion/orientation sensing.

So throughout this comparison, “Nano 33 BLE” refers to the current Rev2 unless the original board is explicitly mentioned.

nRF52840: Designed Around Low-Power Wireless Sensing

The nRF52840 is a very different type of chip from ESP32-S3.

Its core specifications are:

It is particularly strong for:

• BLE sensors;
• wearables;
• keyboards and mice;
• motion devices;
• battery-powered beacons;
• low-power peripherals.

ESP32-S3: Designed for Much More Compute and Networking

Nano ESP32’s ESP32-S3 provides:

This is a much larger computing platform.

It is better suited to:

• web servers;
• MQTT;
• large TLS connections;
• ESP-NOW;
• large JSON documents;
• displays;
• audio buffers;
• MicroPython;
• machine-learning workloads.

CPU Performance

Nano 33 BLE Rev2:

Nano ESP32:

Nano ESP32 has vastly more raw compute throughput.

That matters when running:

• encryption;
• network protocols;
• large filters;
• graphics;
• audio processing;
• machine learning.

But raw CPU performance is not the only design criterion.

The nRF52840 is intentionally optimised around low-power radio and efficient embedded operation.

Hardware Floating Point

The nRF52840’s Cortex-M4 includes a floating-point unit.

This is useful for:

• sensor fusion;
• orientation calculations;
• filters;
• motion processing.

ESP32-S3 is also highly capable of DSP-style workloads and adds vector-oriented instructions aimed at signal-processing and AI acceleration.

Memory: Nano ESP32 Is in a Different Class

Nano 33 BLE Rev2 provides:

Nano ESP32 provides:

The biggest practical difference is the 8 MB PSRAM.

What 8 MB PSRAM Lets You Do

Nano ESP32 is much more comfortable with:

• large framebuffers;
• large web pages;
• large JSON documents;
• audio buffers;
• camera buffers;
• large ML models;
• MicroPython heaps.

Nano 33 BLE Rev2 can run TinyML and sophisticated sensor processing, but memory must be managed much more carefully.

Wi-Fi: Nano ESP32 Wins by Default

Nano 33 BLE Rev2 does not include Wi-Fi.

Nano ESP32 includes:

This means it can connect directly to:

• home routers;
• MQTT brokers;
• HTTP APIs;
• cloud services;
• Home Assistant;
• local web dashboards.

If Wi-Fi is a requirement, Nano ESP32 is the obvious choice.

Bluetooth LE: Both Are Strong

Both boards support Bluetooth Low Energy.

Nano 33 BLE Rev2 is explicitly designed around BLE and uses Arduino’s:

workflow.

Nano ESP32 can use Espressif’s BLE stack and Arduino libraries while simultaneously offering Wi-Fi.

Which Is Better for a BLE-Only Device?

If the project only needs:

• BLE sensor data;
• BLE HID;
• BLE beacon;
• phone connectivity;
• wearable communication;

Nano 33 BLE Rev2 is a very natural fit.

There is little benefit in powering and managing a larger Wi-Fi-capable architecture if Wi-Fi will never be used.

nRF52840 Has IEEE 802.15.4 Hardware

The nRF52840 radio is multiprotocol-capable and supports:

• Bluetooth LE;
• Bluetooth Mesh;
• IEEE 802.15.4;
• Thread;
• Zigbee;
• proprietary 2.4 GHz protocols.

This is an important silicon-level advantage over ESP32-S3, which has no IEEE 802.15.4 radio.

But Arduino’s Nano 33 BLE Workflow Is Primarily BLE

Arduino positions Nano 33 BLE Rev2 mainly as a BLE/Mbed sensor and wearable board.

So while the nRF52840 hardware can support Thread and Zigbee, do not assume the standard Nano 33 BLE Arduino workflow is equivalent to a dedicated Nano Matter or ESP32-C6 Thread development workflow.

If your primary requirement is Matter-over-Thread, use a board designed and documented for that stack.

ESP32-S3 Has No Native Thread Radio

ESP32-S3 supports:

but lacks:

so Nano ESP32 cannot become a native Thread or Zigbee device without external radio hardware.

ESP-NOW Is a Nano ESP32 Advantage

Nano ESP32 supports:

for low-latency peer-to-peer communication between ESP-family devices.

This is useful for:

• remote controls;
• sensor networks;
• wireless buttons;
• small direct device groups.

Nano 33 BLE Rev2 does not use the ESP-NOW ecosystem.

Onboard IMU: Nano 33 BLE Rev2 Wins

Nano 33 BLE Rev2 includes:

Together they provide a 9-axis IMU.

Nano ESP32 does not include an onboard motion sensor.

Why the IMU Matters

For projects such as:

• wearables;
• gesture detection;
• orientation sensing;
• motion logging;
• TinyML classification;
• robot motion tracking;

Nano 33 BLE Rev2 can start working immediately without an external sensor board.

ADC

The nRF52840 includes a:

Nano 33 BLE Rev2 exposes A0-A7 as analog-capable header pins, although A4/A5 are also the I²C pins and have onboard pull-ups.

For clean analog measurements, prefer other analog pins when the I²C bus is active.

Nano ESP32 ADC

ESP32-S3 also provides 12-bit SAR ADC hardware.

Nano ESP32 maps:

For Wi-Fi-heavy analog applications, ADC1 pins are generally the safer default because ADC2 has more resource-sharing constraints.

No True DAC on Either Board

Neither nRF52840 nor ESP32-S3 provides a conventional voltage-output DAC.

Use:

• PWM plus a low-pass filter;
• an external I²C/SPI DAC;
• an external audio DAC/codec.

PWM

nRF52840 includes four four-channel PWM units with EasyDMA.

ESP32-S3 uses the LEDC PWM subsystem and can route PWM to many GPIO through the GPIO matrix.

Both are flexible enough for:

• LED dimming;
• servo control;
• simple audio tones;
• motor-control signals.

USB

Nano 33 BLE Rev2 provides native nRF52840 USB 2.0 Full-Speed through:

Nano ESP32 provides native ESP32-S3 USB through:

Both can support USB device functionality, but Nano ESP32 also includes integrated USB/JTAG debugging.

Debugging

Nano 33 BLE Rev2 exposes SWD pads for external debugging.

Nano ESP32 supports:

without an additional debug probe.

For active firmware development, Nano ESP32’s out-of-box debugging is more convenient.

Security

nRF52840 includes:

• Arm CryptoCell CC310;
• AES acceleration;
• hardware random number generation;
• secure cryptographic features.

ESP32-S3 includes:

• secure boot;
• Flash encryption;
• eFuses;
• cryptographic acceleration;
• hardware key protection.

Both can be used in secure connected products when provisioned correctly.

NFC Is a Nano 33 BLE Advantage

nRF52840 includes:

capability.

This can be useful for:

• tap-to-pair workflows;
• device identification;
• configuration links;
• simple NFC interactions.

Nano ESP32 has no equivalent native NFC peripheral.

Low-Power Design

This is one of the strongest reasons to choose nRF52840.

Nordic designed the device around:

• low-power BLE;
• wearables;
• battery sensors;
• adaptive peripheral power management.

The nRF52840 silicon can reach very low sleep currents.

Actual Nano 33 BLE Rev2 board consumption is higher than chip-only numbers because the development board includes regulators, LEDs and the IMU.

Nano ESP32 Also Supports Deep Sleep

ESP32-S3 provides:

• deep sleep;
• RTC memory;
• ULP processing;
• Wi-Fi/BLE power management.

But Wi-Fi applications typically have a different active-power profile from BLE-only devices.

If the product spends nearly all of its time sleeping and only sends tiny packets over BLE, nRF52840 is often the more natural architecture.

Power Input

Nano 33 BLE Rev2 can be powered from:

• USB;
• VIN;
• VUSB/header paths.

Its onboard MP2322 step-down converter can accept input up to 21 V.

Nano ESP32 also provides a wide:

range.

So both boards integrate more easily into higher-voltage embedded systems than many simple 3.3 V development boards.

Neither Board Has a Built-In Battery Charger

Nano 33 BLE Rev2 documentation explicitly notes that it does not include a battery charger.

Nano ESP32 also requires external battery-management hardware for a rechargeable Li-ion design.

For battery products you will normally add:

• charger;
• protection;
• regulator;
• battery connector.

MicroPython

Both boards support MicroPython.

Nano 33 BLE Rev2 is capable of useful Python sensor applications, but 256 kB RAM imposes real limits.

Nano ESP32 is far more comfortable because it has:

which gives the interpreter and application much more space.

Arduino Software Ecosystem

Nano 33 BLE Rev2

The typical stack includes:

• Arduino Mbed OS core;
• ArduinoBLE;
• Arduino_BMI270_BMM150;
• MicroPython;
• standard Arduino APIs.

Nano ESP32

The typical stack includes:

• Arduino-ESP32;
• WiFi;
• BLE libraries;
• ESP-NOW;
• FreeRTOS APIs;
• ESP-IDF ecosystem;
• MicroPython.

Which Is Better for Wearables?

Nano 33 BLE Rev2 is usually the more natural fit because it combines:

• BLE;
• low-power nRF52840 architecture;
• 9-axis IMU;
• NFC;
• compact Nano format.

Nano ESP32 can absolutely power a wearable, but the onboard IMU and Nordic radio architecture make the BLE board particularly well matched.

Which Is Better for a Wi-Fi Sensor?

Nano ESP32.

Nano 33 BLE Rev2 has no Wi-Fi radio.

Which Is Better for Home Assistant?

If you want:

Nano ESP32 is the easier platform.

If you want a BLE sensor discovered through a BLE proxy or gateway, Nano 33 BLE Rev2 can be a very efficient endpoint.

Which Is Better for TinyML?

The answer depends on the model.

Nano 33 BLE Rev2 is excellent for:

• motion classification;
• gesture recognition;
• wearable inference;

because the IMU is already onboard.

Nano ESP32 has much more memory and CPU headroom for larger models, but you need to add sensors externally.

Which Is Better for Large Displays?

Nano ESP32 is much better because:

allows substantial framebuffers.

256 kB RAM on Nano 33 BLE Rev2 becomes restrictive quickly for graphics-heavy work.

Which Is Better for Audio?

The nRF52840 includes PDM and I²S hardware, but the standard Nano 33 BLE Rev2 does not include an onboard microphone.

Nano ESP32 also supports digital-audio workflows and has far more buffering memory.

If audio processing is significant, Nano ESP32’s larger memory usually gives it the advantage.

Which Is Better for Thread/Zigbee Experiments?

At chip level, nRF52840 is the only one of these two with IEEE 802.15.4.

However, if the primary project goal is modern Arduino Thread/Matter/Zigbee development, a dedicated Nano Matter or ESP32-C6 board is usually a cleaner choice than repurposing Nano 33 BLE Rev2.

Migration from Nano 33 BLE to Nano ESP32

High-level Arduino code using:

is relatively easy to port.

You need to review:

• ArduinoBLE behaviour;
• IMU code;
• nRF-specific low-power APIs;
• Mbed-specific code;
• NFC use;
• pin numbering;
• USB behaviour;
• memory assumptions.

Nano ESP32 Pin Numbering Needs Attention

Nano ESP32 maps Arduino labels onto raw ESP32-S3 GPIO numbers.

For portable code use:

rather than assuming a bare integer always equals the physical ESP32 GPIO number.

Nano 33 BLE Rev2 has a more conventional Arduino pin abstraction.

Decision Table

Requirement	Better fit
BLE-only sensor	Nano 33 BLE Rev2
Wearable	Nano 33 BLE Rev2
Onboard 9-axis IMU	Nano 33 BLE Rev2
NFC	Nano 33 BLE Rev2
Low-power BLE focus	Nano 33 BLE Rev2
Wi-Fi	Nano ESP32
ESP-NOW	Nano ESP32
Maximum CPU performance	Nano ESP32
Largest RAM	Nano ESP32
Largest Flash	Nano ESP32
Large MicroPython application	Nano ESP32
Web server / MQTT / TLS	Nano ESP32
Large display framebuffer	Nano ESP32
802.15.4 silicon capability	Nano 33 BLE Rev2
Native USB debugging	Nano ESP32

Quick Reference

Final Thoughts

Nano 33 BLE Rev2 and Nano ESP32 are both strong compact wireless boards, but they are optimised for different workloads.

Choose Nano 33 BLE Rev2 when you want:

• BLE-first operation;
• low-power sensing;
• an onboard 9-axis IMU;
• wearables;
• NFC;
• Nordic’s nRF52 ecosystem.

Choose Nano ESP32 when you want:

• Wi-Fi;
• much more CPU performance;
• 8 MB PSRAM;
• 16 MB Flash;
• ESP-NOW;
• large MicroPython applications;
• web, MQTT or cloud networking;
• the broader ESP32 ecosystem.

The simplest decision rule is:

For full pin mappings, see our Nano 33 BLE Rev2 pinout guide and Nano ESP32 pinout guide.