Free online ESP32 simulator, running in this tab
Mokxi is a free ESP32 simulator that runs in your browser, with nothing to install and no account needed. It runs eleven ESP32 boards, from the classic ESP32 DevKit on an Xtensa core to the ESP32-S3, C3 and C6, each on the real memory map for its supported peripherals, with your sketch compiled in the tab. The one running here is the ESP32-C3-DevKitM-1.
- 505parts on the bench
- 45boards running now
- 1.00xreal time, on every board
The numbers, not the marketing
Taken from the board's own contract document and put in plain words.
| The core | RV32IMC with Zicsr, machine mode, one instruction per cycle at 160 MHz, passing riscv-tests 67 of 67. |
|---|---|
| Peripherals | GPIO and IO_MUX at their real register offsets, UART0 paced at the configured baud rate and wired to the serial monitor, and the SYSTIMER, which parks the core during delay() rather than spinning on it. |
| WiFi, simulated | The board joins a network, fetches a page and serves one, with the Arduino calls a tutorial gives you. There is no radio and no 802.11 under it. Four made-up addresses under .mokxi answer inside this tab, and signed in you can switch on real internet for HTTP and HTTPS requests to real hosts. |
| What is not there | A radio of any kind: WiFi and Bluetooth LE are simulated, with no radio under either. This page is the DevKitM-1; the XIAO ESP32-C3 and the SuperMini have boards of their own. |
Every ESP32 board here
Three chip families on two instruction sets, each board on its own pinout.
Other ESP32 simulators, honestly
The ESP32 simulator most people already know is Wokwi, and for some projects it is the better choice. Here is the honest split.
Every simulator compared, side by side
Which ESP32 simulator to use, compared
Tinkercad has no ESP32: what to use instead
Wokwi alternatives, compared honestly
Bring a Wokwi ESP32 project across in one step
Start from something that already runs
Every one of these opens in the editor, wired and coded, with nothing to install.
The full board page
Every peripheral area, every example and the wiring notes, in one place.
Step-by-step guides for the ESP32-C3
Each one has the parts, the wiring and the code, and ends in a circuit you can run.
Three steps from a blank tab to a running circuit.
Open the editor
It runs in your browser tab. Nothing to install, and you need no account to start.
Your first projectWire it and write the code
Drag parts onto a breadboard, run each wire from pin to pin, and write the sketch beside it.
WiringPress Run
Your sketch compiles in the tab and runs on a model of the chip, with the Serial Monitor beside it.
Run and serial
Open a project and press Run.
Every one runs in the editor exactly as it is drawn, ready to change.
What makers say about Mokxi.
“The AI checker helps check and correct my circuits, and it has way more components than Tinkercad. As a student I really appreciate the tool.”
“I’d been looking for a real online electronic simulator that was intuitive and complete when I found Mokxi. I was able to quickly import a Fritzing file and my Arduino sketch and start testing. Mokxi has all of the makings for the best online Arduino simulator I have been able to find!”
“I’m using Mokxi to develop and simulate an STM32-based four-wheel-drive robot car before building the actual hardware. It allows me to experiment with DC motor control, PWM, RPM measurement using photointerrupters, and different acceleration, braking, and reversing strategies, helping me understand and refine the system before implementing it in real life.”
Questions, answered.
Which ESP32 boards can I simulate?
Eleven: the ESP32 DevKit V1, the ESP32-DevKitC V4 and the LOLIN32 Lite on the classic Xtensa chip; the ESP32-S3-DevKitC-1, the XIAO ESP32-S3 and the Arduino Nano ESP32 on the S3; the ESP32-C3-DevKitM-1, the XIAO ESP32-C3 and the C3 SuperMini; and the ESP32-C6-DevKitC-1 and the XIAO ESP32-C6. The ESP8266 boards have a page of their own.
Does it simulate WiFi?
Yes, and it says so: the Arduino WiFi, HTTPClient and WebServer calls over a simulated network. There is no radio and no 802.11 behind it. A sketch can fetch and serve pages on addresses under .mokxi, and signed in you can switch on real internet to reach a real API over HTTP or HTTPS.
Does it simulate Bluetooth or MQTT?
Bluetooth, yes, simulated: BluetoothSerial and the BLE server talk to a phone in the editor’s Bluetooth pane, with no radio under it. MQTT, no: the network carries HTTP only, so an MQTT client compiles but cannot reach a broker. Wokwi simulates MQTT, if your project depends on it.
Can I write MicroPython or ESP-IDF code?
MicroPython, on the classic ESP32 boards (the DevKit V1, the DevKitC and the LOLIN32 Lite) and the Raspberry Pi Pico: choose MicroPython (main.py) in the board’s Firmware panel and the official firmware runs it. The other ESP32 boards run Arduino-style C++, compiled in the tab; for ESP-IDF or Rust on a simulated ESP32, Wokwi supports both.
Will my firmware run on a real board?
Firmware for the modeled peripherals targets the real register offsets. On the ESP32-C3, Upload to board (Beta) writes a hardware build to the board over Web Serial. Test the finished build on the board before relying on it.
Is it free?
Yes, every ESP32 board is on the free plan, with no card and no account needed to try it.
Do I need an account at all?
No. The editor, the templates, the gallery, the compiler and Run all work without signing in. Your browser keeps your work as you go. An account saves your projects online, so they follow you to any computer. It also gives you a link to share.
Which boards are supported?
Forty-five, all on the free plan. Arduino: the Uno R3, Uno R4 Minima and Uno R4 WiFi, Nano, Nano ESP32, Nano RP2040 Connect, Mega 2560, Leonardo, Micro, the Pro Mini in its 5 V and 3.3 V builds, and the SparkFun Pro Micro. ESP32: the classic DevKit V1, the ESP32-S3, the ESP32-C3 and C6 DevKits, the Espressif DevKitC V4, the Freenove ESP32-WROVER, the Wemos LOLIN32 Lite, the Wemos D1 R32, the Cheap Yellow Display, the TTGO T-Display, the ESP32-C3 SuperMini and the Seeed XIAO ESP32-C3, C6 and S3. ESP8266: the NodeMCU, the Wemos D1 mini and the ESP-01S. Also the Raspberry Pi Pico and Pico W, the Seeed XIAO RP2040, the Waveshare RP2040-Zero, the Seeed XIAO SAMD21, the WCH CH32V003, the STM32F411 Black Pill, the STM32 Nucleo-F411RE and the STM32F103 Blue Pill, the BBC micro:bit V2, and the ATtiny85 and the ATmega328P in its 16 MHz and 8 MHz builds, which plug straight into the breadboard as bare chips. Your own code compiles in the browser for all of them. Then the Raspberry Pi 4, Pi 5 and Zero 2 W computers, which run your Python with gpiozero and RPi.GPIO, with nothing to compile. Each board page lists what it can and can’t do. For example, the WiFi boards have pretend WiFi, not a real radio, and the page says so.
Is my sketch really compiled in the browser?
Yes. A real compiler (clang, built for the web) runs in your browser. It downloads once, and your browser keeps a copy. After that, every build happens on your own computer. There is no build server and no waiting in line, so there are no build minutes to run out of.
Which browsers work?
Any up-to-date Chrome, Edge, Firefox or Safari, on a computer, a phone or a tablet. They all support WebAssembly, which Mokxi needs, and they have for years.
Does it work on a phone?
Yes. The editor works with touch, the buttons are big enough to tap, and the layout fits a small screen. The simulation runs on the phone itself.
Can I try Pro before I pay?
Yes. Every account can try Pro free for 7 days, once. It takes a card, nothing is charged for those days, and if you cancel before they end you pay nothing. It starts when you choose it.
Can I cancel anytime?
Yes, in one press from your account page. Your plan runs to the end of what you paid for.
Do you offer refunds?
Yes, once per account. Write to us within 14 days of a payment and we refund all of it. Lifetime Pro is refunded in full within 14 days of buying it.
Is there a student discount?
Yes. Students get Pro at half price with a school email.
Do students need accounts?
No. The simulator works signed out, so your class starts from one link with nothing to sign up for. An account only adds cloud saving and sharing, and a student can make one later, or never.
Does it work on a Chromebook?
Yes. Everything runs on the machine in front of the student, so a Chromebook works as well as a lab PC.
What does it cost for a class?
Nothing, if your students only need to open and run circuits: the whole simulator is on the free plan. The class tools (a roster, starter projects, auto-graded checks, the gradebook) come with Pro and Classroom. Classroom is $9.99 a student a year, from 5 students, so at least $49.95 for the year. Your own seat is free, and from 50 students each one costs less. Your students get Pro’s room while they are in your classes. Pay by card, invoice or purchase order. Pro on its own runs classes for up to 10 students in all. To try the class tools with real students first, start the free 30-day trial from your class page: one class of up to 20 students, no card.
Is student work private?
Yes. A student’s projects in a class are always private: they cannot be opened by link or put in the gallery. One exception, and only for reading: a teacher may open, and never write, a project owned by somebody in a class they teach, which is what a card on the class wall does. What we store about a student, who processes it, how a school has it deleted, and how we handle COPPA consent for students under 13 and FERPA as a school official are all on the student data privacy page at /privacy/students.
Is Mokxi AI free?
Every signed-in account gets questions every day: 5 on a free account, 50 on the Pro trial, 100 on Pro and the other paid plans, and 25 on Lifetime Pro.
Does Mokxi AI work with ESP32 and Raspberry Pi Pico sketches?
Yes. It knows which board the project is on and answers for that board, from an Uno to an ESP32, an ESP8266, a Pico or an STM32.
Can Mokxi AI change my code without asking?
No. It proposes a change as a card. Accept is yours, and only appears once the changed code compiles; Ctrl+Z undoes it.
What does Mokxi AI send with a question?
Your project text, the matching help articles and the last six messages of the chat, never your name or account. "What is sent" shows exactly what went.
Latest arrivals in Mokxi.
Simulators for one kind of circuit
A servo, a display, a motor driver or a rectifier, each already running.
Try your own firmware on the ESP32-C3
What you build here runs on the board on your desk, unchanged. Nothing to install and no account needed.





