Open the editorEditor

Electronics that run, in a browser tab.

Mokxi is a free electronics simulator that runs in your browser. Build and run Arduino, ESP32, Pi Pico and STM32 circuits, with no installs or hardware needed to start.

Start building freeOpen the editorContinue buildingMy projects
New to electronics? Build your first circuit wire by wire
Stackerlive0.000 s 0.00x
++−−++−−jjiihhggffeeddccbbaa115510101515202025253030ESP32-C3MINI-1ESP32-C3-DevKitM-1GND3V33V323RSTGND0110456785V5VGNDGND918192021NCNCNCNCNCNCRGB8BOOTRST12MAX7219MAX7219
Tap to start
Real ESP32-C3 firmware. Click to open it and play.
Your bench

Everything in the parts bin

Here's every part waiting for you, each one drawn by the very code the editor runs.

Full-size breadboard
A real 0.1 inch grid with the rails and the center channel, 63 columns wide.
Jumper wires
Drag from any pin or hole to any other. Corners snap, and you can drag them.
5V
Power
A supply rail at the voltage you choose.
Ground
The other end of every circuit.
LED
Lights when current flows. Five colors, and the brightness is what your eye would see.
Filament lamp
A tungsten bulb in a holder: an inrush when it is switched on cold, tens of milliseconds to warm up, and dim on half its voltage.
Resistor
Any value you like, with the color bands drawn to match.
ESP32-C3-DevKitM-1
A RISC-V board that runs your firmware at 160 MHz on the real memory map.
Pushbutton
A 12 mm tactile switch. Hold it while the simulation runs.
Raspberry Pi Pico
The RP2040 board on our own Cortex-M0+ core. Pick a program and press Run.
Raspberry Pi Pico W
Raspberry Pi Pico W (RP2040). The same board and the same pinout as a Pico, with the CYW43439 on it. The WiFi is simulated (no radio; real internet through the Cloud panel’s switch), and the on-board LED, which hangs off that chip rather than off GP25, is driven through the same path. Everything else is the Pico.
Raspberry Pi 4 Model B
Raspberry Pi 4 Model B: the 40-pin header, driven by main.py with RPi.GPIO or gpiozero.
See every part
Boards

Real boards, built from the datasheets

Each board has its own memory map. Open its page to see what runs here, what transfers to hardware, and what the model does not cover yet.

ESP32-C3-DevKitM-1

A RISC-V chip at 160 MHz, on the real memory map.

Open the board page
Arduino Uno R3

The classic Arduino, with an ATmega328P running at 16 MHz.

Open the board page
Arduino Nano

The Uno’s chip on a small board that fits a breadboard.

Open the board page
Arduino Mega 2560

The big Arduino, with 54 digital pins and four serial ports.

Open the board page
Arduino Leonardo

An Uno-shaped board whose chip does its own USB serial.

Open the board page
ESP32-C6-DevKitC-1

A second RISC-V board, with 31 pins and simulated WiFi.

Open the board page
ESP32 DevKit V1

The classic ESP32 at 240 MHz, with simulated WiFi.

Open the board page
ESP32-S3-DevKitC-1

The ESP32-S3 at 240 MHz, with USB serial and an RGB LED.

Open the board page
All 39 boards

Compiles in your browser. No build queue. How fast, measured

Anywhere

It works with a finger

  • Drag a part, drag a wire and hold a button, all with one finger.
  • Panes stack on a narrow screen and the canvas keeps its own gestures.
  • The simulation runs on the phone itself, and no account is needed.
Start building freeOpen the editor
The Mokxi editor on a phone-sized screen, running Ring Simon on an ESP32-C3 with the sketch below the circuit.
Plans

What it costs

Free
$0forever
  • Unlimited building and simulation
  • Every board and part
  • 10 public projects
  • 10 questions to Kix AI a day
  • Real internet for WiFi boards
Start free

or try it without an account

ProMost popular
$10per month
  • Everything in Free, plus:
  • Upload to your real board
  • Full schematic and KiCad
  • PCB and ordering
  • Build guide and Shopping list
  • Every export
  • Unlimited projects, private too
  • And more
Classroom
$10per student, per year
  • Everything in Pro, plus:
  • Every student gets Pro
  • Your own seat free
  • From 5 students
  • Pay by card, invoice or purchase order
  • 30 days free for 20 students
Price your class

or try it free for 30 days

Compare every plan
Projects

Open one and press Run

Each one is drawn from its own diagram and runs exactly as you see it.

Blink and press
A pushbutton and a 2 Hz clock, no processor in sight.
BeginnerBuilt in
ESP32-C3 knight rider
An ESP32-C3 sweeps a bright dot back and forth along six LEDs, one GPIO each.
BeginnerESP32-C3-DevKitM-1Built in
Uno Pong console
An Uno, a 240x320 TFT, a thumb stick and a piezo: a paddle game in the window an Uno can repaint.
AdvancedArduino Uno R3Built in
ESP32-C3 Simon
Four LEDs flash a growing sequence, four buttons play it back.
AdvancedESP32-C3-DevKitM-1Built in
Uno reaction duel
Two buttons, three lamps and a piezo: the Uno lights the middle lamp and the first press wins.
IntermediateArduino Uno R3Built in
ESP32-C3 Morse sender
An ESP32-C3 sends a word in Morse on a lamp and a piezo at once, and a button picks the next message.
BeginnerESP32-C3-DevKitM-1Built in
Pico chaser
A dot sweeps back and forth along six LEDs on GP2 to GP7, one GPIO each.
BeginnerRaspberry Pi PicoBuilt in
See every project
Community

What people are building

Projects people have made and shared. Open one, press Run, and remix it.

See what people are building
In brief

What Mokxi is

Mokxi is a free electronics simulator that runs in your web browser. Wire a breadboard, write C++ firmware and press Run, even on a school Chromebook.

  • Runs in your browser
  • No install, no account to start
  • Every board and part free

Simulators

Teachers and schools

Start learning

Every board (43)

Compare all boards
Arduino
ESP32 and ESP8266
Raspberry Pi
STM32
More boards

One circuit, already running

The online circuit simulator

Build something

Open the editor and make one of these circuits yours.

Start building freeOpen the editor