Arduino MKR WiFi 1010 vs Nano 33 IoT: Same SAMD21 and Wi-Fi, Different Boards

The Arduino MKR WiFi 1010 and Arduino Nano 33 IoT are much more similar than their different form factors suggest.

Both use the same core architecture:

That means their raw processing performance and wireless capability are essentially the same.

The real choice is:

Quick Comparison

Feature	MKR WiFi 1010	Nano 33 IoT
Main MCU	SAMD21 Cortex-M0+	SAMD21 Cortex-M0+
Clock	48 MHz	48 MHz
Flash	256 KB	256 KB
SRAM	32 KB	32 KB
EEPROM	No dedicated EEPROM	No dedicated EEPROM
Logic voltage	3.3 V	3.3 V
Wi-Fi	NINA-W102	NINA-W102
Bluetooth	Yes	Yes
Secure element	ATECC508	ATECC608A
Analog inputs	7	8
True DAC	1 × 10-bit	1 × 10-bit
PWM	13 documented pins	11 documented pins
Hardware UART	1	1
SPI	1	1
I2C	1 + Eslov connector	1
IMU	No	LSM6DS3 6-axis
Li-Po charger	Yes	No
Battery connector	Yes	No
Length	61.5 mm	45 mm
Width	25 mm	18 mm
Weight	About 32 g	About 5 g with headers

Same SAMD21 Processor

Both boards use the:

running at:

with:

So there is no meaningful CPU-performance reason to choose one board over the other.

A computation-heavy sketch that fits on one will generally perform almost identically on the other.

Same Wireless Module

Both use the:

for:

This also means the same core Arduino libraries can be used for most wireless projects.

WiFiNINA Compatibility

Both boards use:

for Wi-Fi applications.

That makes code migration between them straightforward.

For example:

works from the same basic architecture on both boards.

ArduinoBLE Compatibility

The same is true for BLE projects using:

because both boards use the same NINA wireless module family.

Arduino Cloud Support

Both boards are current Arduino Cloud-compatible devices.

That makes them suitable for:

• cloud dashboards;
• remote sensor monitoring;
• phone-controlled BLE devices;
• Wi-Fi telemetry;
• home automation.

Both Are 3.3 V Boards

The most important electrical rule for either board is:

Neither should be treated like an older 5 V Nano or UNO.

Arduino explicitly warns that direct 5 V signals can damage these boards.

GPIO Current Is Also Similar

Arduino specifies approximately:

for both boards.

Use external drivers for:

• relays;
• motors;
• solenoids;
• high-current LEDs.

MKR WiFi 1010 Has Seven Analog Inputs

The MKR board exposes:

for seven analogue inputs.

A0 also provides:

Nano 33 IoT Has Eight Analog Inputs

The Nano exposes:

for eight analogue inputs.

That gives Nano 33 IoT one extra analogue-capable header pin.

Nano A4/A5 Are Primarily I2C Pins

Arduino notes that:

include internal pull-ups and are intended to default to I2C use.

Arduino therefore does not recommend using them casually as analogue inputs even though they have analogue capabilities.

Both Include a True DAC

Both boards use the SAMD21’s:

and can provide a true:

rather than only PWM.

PWM Counts Differ

MKR WiFi 1010 has 13 documented PWM-capable positions.

Nano 33 IoT has 11 documented PWM pins:

The difference comes from the different header routing and board layouts, not from a fundamentally different MCU.

Nano 33 IoT Has a Built-In IMU

This is the biggest functional advantage of Nano 33 IoT.

It includes an:

6-axis IMU containing:

What the IMU Enables

The onboard IMU is useful for:

• motion sensing;
• tilt detection;
• pedometers;
• gesture projects;
• vibration monitoring;
• robot orientation;
• movement alarms.

With MKR WiFi 1010, you need an external IMU for the same functions.

MKR WiFi 1010 Has Li-Po Charging

The MKR board includes:

and is designed to switch automatically between external power and battery operation.

Arduino recommends a battery of at least:

for the MKR WiFi 1010 charging system.

Nano 33 IoT Has No Battery Charger

The Nano 33 IoT:

You can still run it from a battery, but the power source and charging system must be external.

This Is a Major Design Difference

For a portable IoT device:

Nano 33 IoT Is Much Smaller

The Nano measures:

while the MKR WiFi 1010 measures:

The Nano is therefore much easier to fit inside:

• small enclosures;
• wearables;
• robots;
• compact sensors;
• breadboard prototypes.

Nano 33 IoT Is Breadboard-Friendly

The Nano format is designed to straddle a standard solderless breadboard.

This makes quick prototyping very convenient.

The MKR board is still compact, but it uses the wider MKR form factor.

MKR WiFi 1010 Supports MKR Shields

The MKR form factor gives access to the Arduino MKR shield ecosystem.

Examples include:

• MKR ETH Shield;
• MKR CAN Shield;
• MKR Relay Proto Shield;
• MKR Motor Carrier;
• MKR IoT Carrier.

MKR WiFi 1010 Has the Eslov I2C Connector

The MKR board includes a dedicated:

carrying:

• SDA;
• SCL;
• GND;
• 5 V power;
• wake/alarm signal.

This can simplify modular sensor connections.

Nano 33 IoT Does Not Have Eslov

On Nano, I2C devices normally connect through:

on the standard Nano headers.

SPI Pin Layout Is Different

MKR WiFi 1010 uses:

Nano 33 IoT uses the more Nano-like arrangement:

This is important when moving hardware between the boards.

I2C Layout Is Different

MKR WiFi 1010:

Nano 33 IoT:

So a sketch may remain the same if it uses:

but physical wiring will change.

UART Layout Is Different

MKR WiFi 1010 uses:

while Nano 33 IoT follows the Nano-style:

for the external hardware UART.

Software Migration Is Still Easy

If your code uses Arduino abstractions such as:

the same sketch often requires little or no software change.

The biggest migration task is usually:

Secure Element Difference

MKR WiFi 1010 includes:

while Nano 33 IoT uses the newer:

Both provide secure hardware support for:

• device identity;
• private keys;
• certificates;
• secure cloud authentication.

Both Boards Use Native USB

The SAMD21 includes native:

so both boards can support:

• USB CDC serial;
• USB HID;
• native USB device applications.

Both use Micro-USB connectors rather than the USB-C used on newer Arduino boards.

NINA-W102 Pins Are More Exposed on Nano 33 IoT

Arduino documents several Nano 33 IoT header pins that can also be driven directly by the NINA-W102’s ESP32 processor if the corresponding SAMD21 pins are tri-stated.

These include connections associated with:

This is an advanced use case rather than normal Arduino operation.

Direct NINA Control Requires Care

If the NINA drives a shared pin, the corresponding SAMD21 pin must not drive against it.

The rule is the same as any shared-bus system:

MKR WiFi 1010 Power Input

Arduino specifies the MKR VIN input around:

regulated.

Do not treat it like the wide-range VIN input of an older UNO or Mega.

Nano 33 IoT Power Input

The Nano uses a different power path and Arduino currently specifies a relatively wide VIN input limit.

The board still operates internally at:

and remains not 5 V tolerant at its GPIO.

Nano 33 IoT 5 V Pin Has a Jumper Caveat

Arduino documents that the Nano’s 5 V pin only provides USB 5 V when the rear:

is bridged.

If powered through VIN, the board does not create a regulated 5 V output on that pin.

MKR WiFi 1010 Is Better for Battery IoT

If the project must:

• run from Li-Po;
• charge from USB;
• switch automatically between battery and USB;

MKR WiFi 1010 has the cleaner solution.

Nano 33 IoT Is Better for Motion-Sensing IoT

If the project needs:

• accelerometer;
• gyroscope;
• movement detection;
• tilt;
• vibration monitoring;

Nano 33 IoT provides those functions without an external sensor.

Nano 33 IoT Is Better for Compact Embedded Builds

The:

form factor makes it easier to embed in small devices.

It is also significantly lighter.

MKR WiFi 1010 Is Better for MKR Carrier Boards

If you already use:

• MKR shields;
• MKR IoT Carrier;
• MKR-specific hardware;

the MKR WiFi 1010 is the natural fit.

Which Is Better for a Basic Wi-Fi Sensor?

Performance is effectively the same.

The choice comes down to hardware:

Which Is Better for BLE?

Both use the same NINA-W102 radio architecture, so neither has a significant core BLE-performance advantage.

Which Is Better for Arduino Cloud?

Both are officially compatible.

Choose based on:

• physical size;
• battery requirements;
• IMU requirement;
• shield ecosystem.

Which Has More I/O?

The answer depends on what you count.

Nano 33 IoT offers:

while MKR WiFi 1010 exposes a different MKR layout with:

and more documented PWM positions.

For a real project, compare the exact required:

• ADC channels;
• PWM pins;
• SPI pins;
• I2C pins;
• UART pins;

rather than relying on one headline I/O number.

Decision Table

Requirement	Better fit
Smallest board	Nano 33 IoT
Breadboard use	Nano 33 IoT
Built-in IMU	Nano 33 IoT
Li-Po charging	MKR WiFi 1010
Battery connector	MKR WiFi 1010
MKR shields	MKR WiFi 1010
Eslov connector	MKR WiFi 1010
Wi-Fi performance	Essentially the same
BLE capability	Essentially the same
CPU performance	Same
RAM / Flash	Same
Arduino Cloud	Both
True DAC	Both

Quick Reference

Final Thoughts

The MKR WiFi 1010 and Nano 33 IoT are essentially the same processing and wireless platform packaged for different kinds of projects.

Choose MKR WiFi 1010 when you need:

• Li-Po charging;
• battery connector;
• MKR shields;
• Eslov I2C;
• a more carrier-oriented IoT platform.

Choose Nano 33 IoT when you need:

• smaller size;
• breadboard use;
• lower weight;
• built-in accelerometer and gyroscope;
• a compact embedded sensor node.

Do not choose between them based on CPU speed, RAM, Flash or Wi-Fi performance because those are essentially the same.

The decision is mainly:

For detailed MKR pin mapping, see our MKR WiFi 1010 pinout guide. For the broader MKR family, see Arduino MKR boards compared. For Nano 33 IoT pin details, see our Arduino Nano 33 IoT pinout guide.