The Arduino Nano is one of the most enduring microcontroller boards ever made. Launched in 2008, its compact form factor, breadboard-friendly layout, and low cost made it a staple in maker labs, robotics projects, and professional prototypes worldwide. The Arduino Nano Every arrived in 2019 as its direct successor — same physical size, same pinout, updated silicon.
In 2026, both boards are still in active production and sale. The original Nano remains popular because of its vast ecosystem of tutorials and shields; the Nano Every offers meaningfully better specs at a comparable price. This guide gives you the complete picture so you can make an informed choice for your next project.
Quick Specs Comparison
| Specification | Arduino Nano | Arduino Nano Every |
|---|---|---|
| Microcontroller | ATmega328P | ATmega4809 |
| Architecture | AVR (8-bit) | AVR (8-bit) |
| Clock Speed | 16 MHz | 20 MHz |
| Flash Memory | 32 KB | 48 KB |
| SRAM | 2 KB | 6 KB |
| EEPROM | 1 KB | 256 bytes |
| Digital I/O pins | 22 | 20 |
| Analog inputs | 8 | 8 |
| PWM channels | 6 | 5 |
| UART ports | 1 | 1 |
| I2C buses | 1 | 1 |
| SPI buses | 1 | 1 |
| Operating Voltage | 5 V | 5 V |
| Input voltage range | 7–12 V | 7–21 V |
| Dimensions | 45×18 mm | 45×18 mm |
What Changed: ATmega328P to ATmega4809
The most significant change between the two Nanos is the microcontroller itself. The original Nano uses the ATmega328P, the same chip as the Arduino Uno — a well-understood 8-bit AVR core that has been manufactured since 2006. The Nano Every uses the ATmega4809, a member of Microchip’s newer megaAVR 0-series family, introduced around 2018.
The ATmega4809 is a fundamentally newer design with several architectural improvements over the 328P:
- Higher clock speed: 20 MHz vs 16 MHz — a 25% increase that directly speeds up all computation and communication.
- Internal oscillator accuracy: The 4809’s internal oscillator is far more accurate than the 328P’s, allowing use without an external crystal in many applications.
- UPDI programming interface: Replaces the older SPI-based ISP (In-System Programming). UPDI uses a single wire, which is simpler to implement in custom hardware.
- CCL (Configurable Custom Logic): Built-in programmable logic cells that can perform glue logic operations in hardware without involving the CPU — a feature unheard of on the 328P.
- Event System: Hardware-level peripheral interconnects that let timers, ADCs, and pins communicate without CPU involvement, enabling ultra-low-latency responses.
For the vast majority of projects, the CCL and Event System are advanced features you’ll never touch. But the extra speed and RAM are immediately felt in any moderately complex sketch.
Memory Upgrade: More RAM, More Flash
The memory difference is the most practical reason to choose the Nano Every in 2026:
- Flash: 48 KB vs 32 KB — 50% more program storage. The Arduino bootloader uses about 2 KB on each board, leaving 30 KB (Nano) vs 46 KB (Every) for your sketch. This becomes critical when you’re using multiple libraries simultaneously.
- SRAM: 6 KB vs 2 KB — the most impactful difference for most projects. Three times the RAM means you can use the Arduino
Stringclass more freely, buffer more serial data, allocate larger arrays, and use libraries that require significant heap space (JSON parsers, display libraries).
The one memory regression: EEPROM drops from 1 KB on the 328P to 256 bytes on the 4809. If your project stores significant configuration data in EEPROM, you’ll need to be more careful about storage layout — or use external I2C EEPROM.
Peripherals and Communication Interfaces
I2C: Different Pins
This is the most important compatibility gotcha. On the classic Nano, I2C uses pins A4 (SDA) and A5 (SCL) — identical to the Uno. On the Nano Every, I2C is on pins A4/A5 but also brought out to dedicated pads. The Wire library targets the correct pins automatically, so most code works without changes. However, if you’re using a custom shield designed for the Nano that manually addresses I2C pins, verify the pinout.
Serial: TX/RX Same Pins, Different Behavior
The Nano Every uses a different USB-to-serial chip (the SAMD11D14A), which handles USB communication differently from the original Nano’s FT232 (clones often use CH340). The behavior is nearly identical from the user’s perspective, but you may need to install a driver on first connection on Windows.
PWM: One Fewer Channel
The Nano Every has 5 hardware PWM channels vs 6 on the classic Nano. This is rarely a limiting factor unless your project specifically drives 6 independent PWM outputs.
Power Consumption
Both boards operate at 5 V and draw similar current in active mode — roughly 15–20 mA for the board itself plus whatever peripherals you attach. The Nano Every’s sleep modes are more flexible and achieve lower quiescent current (the 4809 can reach ~1 µA in deep sleep vs ~0.75 µA for a well-configured 328P), but the difference is minimal for most battery projects.
For serious battery-powered applications, neither board is ideal as-is — both draw significant current through the onboard voltage regulators and USB interface chips even in sleep mode. Purpose-built low-power boards or raw microcontroller circuits are better choices for ultra-low-power designs.
Library and Code Compatibility
This is where users most commonly encounter friction when upgrading from Nano to Nano Every.
Arduino Core Boards Package Required
The Nano Every requires the Arduino megaAVR Boards package (or the newer Arduino AVR Boards package v1.8.6+, which includes megaAVR support). If you open a project last uploaded to a Nano and select Nano Every without installing this package, the upload will fail.
- Arduino IDE → Tools → Board → Board Manager
- Search for “megaAVR” and install Arduino megaAVR Boards
- Select Arduino Nano Every under this package
Libraries That May Behave Differently
- SoftwareSerial: Works but may have timing differences at higher baud rates due to the different clock and interrupt architecture.
- IRremote: Most versions work; ensure you use a version that supports megaAVR.
- Low-power libraries: Libraries written for ATmega328P sleep modes (like LowPower.h) need megaAVR-compatible versions.
- Direct port manipulation: Code using
PORTB,DDRD, etc. won’t work on the 4809 — its port register layout is different. UsepinMode()/digitalWrite()for compatibility.
Generally Compatible
Standard library code using digitalRead(), digitalWrite(), analogRead(), Wire, SPI, Serial, servo, and most sensor libraries will compile and run without modification. The Arduino team made significant compatibility efforts when designing the Nano Every.
Which Should You Choose?
Choose the Arduino Nano (classic) if:
- You have existing code that uses direct port manipulation (PORTB/DDRD style) and don’t want to rewrite it
- Your existing shield or custom PCB is designed for the 328P pinout and serial chip
- You need more than 256 bytes of EEPROM without adding external hardware
- You’re following a specific tutorial that was written for the classic Nano
Choose the Arduino Nano Every if:
- You’re starting a new project from scratch — the extra RAM alone makes it worth it
- Your sketch uses large libraries (WiFi, display, JSON parsing) and the Nano runs out of memory
- You need the faster 20 MHz clock for tight timing requirements
- You want a wider VIN range (7–21 V) for direct connection to common battery voltages like 12 V
In 2026, for any new project that doesn’t have a specific reason to use the older chip, the Nano Every is the better default choice. The 3× RAM increase is a quality-of-life improvement that prevents the most common source of mysterious bugs in Arduino projects.
Beyond the Nano: When to Upgrade Further
Both Nano variants will hit their limits in certain project categories:
- Need wireless? → Arduino Nano 33 IoT (WiFi + BLE) or Arduino Nano 33 BLE Sense (BLE + IMU + microphone)
- Need machine learning? → Arduino Nano RP2040 Connect (dual-core, 264 KB SRAM, WiFi) or Arduino Nano 33 BLE Sense
- Need many I/O pins? → Arduino Mega 2560 (54 digital pins, 16 analog inputs)
- Need more processing power? → Arduino Due (84 MHz ARM Cortex-M3, 96 KB SRAM, 512 KB Flash)
Frequently Asked Questions
Is the Arduino Nano Every a drop-in replacement for the Arduino Nano?
Physically yes — same 45×18 mm PCB, same 30-pin header layout, compatible with Nano-sized breadboard shields. In software, most Arduino library code is compatible without changes. The main exceptions are direct port manipulation code (PORTB/DDRD registers) and some low-power libraries that were written specifically for the ATmega328P architecture.
Can I program the Nano Every with Arduino IDE 1.8.x?
Yes, but you must install the Arduino megaAVR Boards package via the Board Manager. Arduino IDE 2.x is recommended in 2026 for better debugging tools, faster compilation, and improved Library Manager. Both IDEs support the Nano Every fully once the correct board package is installed.
Why does the Nano Every have less EEPROM than the classic Nano?
The ATmega4809’s design prioritizes SRAM and Flash over EEPROM, reflecting how modern embedded development has shifted — more application state is managed in RAM or external storage rather than EEPROM. The 256 bytes of EEPROM is sufficient for most configuration data (WiFi credentials, calibration offsets, settings). If you need more, an external AT24C32 I2C EEPROM provides 4 KB for a few rupees.
Does the Nano Every support 5V and 3.3V peripherals?
The Nano Every operates at 5 V logic level. Connecting 3.3 V peripherals directly to its GPIO pins risks damaging the peripheral if the Arduino outputs 5 V to a 3.3 V-only input. Use a voltage divider or level shifter for 3.3 V devices. The board does provide a 3.3 V power pin (limited to ~50 mA) for powering 3.3 V sensors, but the GPIO logic is 5 V.
What happened to the Arduino Nano Every between 2019 and 2026?
The Nano Every has remained fundamentally unchanged in hardware. Arduino has continued to improve the board support package (core) for the megaAVR series, fixing bugs and improving library compatibility. As of 2026, the megaAVR core is mature and stable. The Nano Every remains in active production and is the recommended Nano for new designs that don’t require wireless.
Conclusion
The Arduino Nano vs Nano Every decision in 2026 is clearer than ever: the Nano Every is the better board for new projects in almost every measurable way — more Flash, three times the RAM, faster clock, wider input voltage range, and better peripheral architecture. The classic Nano remains valuable for projects with specific compatibility requirements or when following legacy tutorials.
If you’re building something new today, pick the Nano Every. If you need wireless, pick the Nano 33 IoT. If you need raw I/O count, step up to the Mega. The Nano family covers a broad range of project needs with a consistent, compact form factor that fits almost anywhere.
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