Raspberry Pi 3 Simulator
Python · GPIO · I2C — In Your Browser
Run Raspberry Pi projects in your browser: write Python against the circuit on the canvas with RPi.GPIO, gpiozero and smbus2, the libraries real Pi projects use. Scripts start in seconds on the in-browser engine; a Linux guest on our servers is one click away when a script needs a shell.
In-browser Python · QEMU Linux guest · Three free trial sessions, then Maker and Pro plans
What can you do with the Pi 3 simulator?
Velxio runs your Raspberry Pi scripts against the sensors, displays and actuators you wire on the canvas — the same component models an Arduino or ESP32 talks to. Two engines: Python in the browser by default, and a QEMU Linux guest when you want a terminal.
Run Python Scripts
Python 3 with RPi.GPIO, gpiozero, smbus2 and pyserial. GPIO in and out, PWM, UART and I2C sensors on the header bus; third-party packages through a requirements.txt.
GPIO Control
Use RPi.GPIO or gpiozero to control LEDs, read buttons, drive motors — real GPIO emulation in QEMU.
Linux Terminal
Optional Linux mode boots an Alpine guest in QEMU with a real shell and python3. It is not Raspberry Pi OS: no apt, no desktop, no network from inside the guest.
ARM Cortex-A53
The Linux guest runs a 64-bit ARM kernel under QEMU (32-bit for the Zero, 1 and 2) with the CPU profile of the board you picked.
No SD Card Needed
The OS image is pre-loaded. No flashing, no SD card, no power supply — just open the browser and start coding.
Multi-Board Canvas
Mix Raspberry Pi 3 with Arduino and ESP32 on the same simulation canvas. Control Arduino from Pi via serial.
Raspberry Pi Pico vs Pi 3 — which to choose?
Raspberry Pi Pico (RP2040)
Microcontroller. ARM Cortex-M0+ at 133 MHz. Runs Arduino C++ code. No OS, bare-metal. Best for embedded, IoT, sensors. Try Pico Simulator →
Raspberry Pi 3 (ARM Cortex-A53)
A Linux single-board computer. Runs Python scripts against the canvas, in the browser or in a QEMU guest with a shell. Best for GPIO scripting, sensors over I2C, automation and education.
Frequently Asked Questions
- Can I simulate a Raspberry Pi 3 in my browser?
- Yes. Velxio runs Raspberry Pi projects (Zero through Pi 5) in your browser: Python scripts execute against the circuit on the canvas, and a Linux guest under QEMU gives you a terminal when a script needs one. The guest is Alpine Linux, not Raspberry Pi OS.
- Is the Raspberry Pi simulator included in the free plan?
- Partly. You can build and save a Raspberry Pi circuit with any account, and a free account gets three 15-minute trial sessions to run it (every run inside a session is free). Unlimited Raspberry Pi Linux emulation runs a full ARM guest on our servers, so it is part of the Maker and Pro plans, or of Velxio Desktop with a paid licence. The editor and the Arduino, ESP32 and Raspberry Pi Pico simulators are free and need no account. Velxio itself stays open-source (GNU AGPLv3).
- Can I run Python scripts on the Raspberry Pi simulator?
- Yes. Python 3 runs in the browser with RPi.GPIO, gpiozero and smbus2, or in the Linux guest. Third-party packages are installed from a requirements.txt in your project; pip cannot reach the internet from inside the guest.
- What is the difference between Pi Pico and Pi 3 simulation?
- Raspberry Pi Pico (RP2040) is a microcontroller — it runs Arduino C++ or MicroPython, no OS. Raspberry Pi Zero through 5 are Linux computers — they run Python scripts, and in Linux mode a shell. Velxio supports both.
- Does it support GPIO on Raspberry Pi 3?
- Yes. RPi.GPIO and gpiozero drive LEDs, read buttons and PIR sensors, and PWM reaches servos and dimmed LEDs. I2C sensors on the header bus (SDA on GPIO2, SCL on GPIO3) answer through smbus2. A Pi has no analog input: a potentiometer needs an MCP3008 or ADS1115 between it and the Pi.
Ready to simulate Raspberry Pi 3?
Open the editor, select Raspberry Pi 3, and boot into Linux — right in your browser.
Launch Pi 3 Simulator →