XIAO ESP32S3 Simulator
the thumbnail-sized ESP32-S3, free in your browser
Simulate Seeed Studio's XIAO ESP32S3: Arduino C++, MicroPython and ESP-IDF on an in-browser ESP32-S3 engine, wired to 100+ components with real-time SPICE analog simulation.
Free plan · No install, no account · Runs in your browser
XIAO ESP32S3 at a glance
The XIAO ESP32S3 is the same dual-core Xtensa LX7 silicon as the ESP32-S3 DevKit with only the pins that fit on a board the size of a thumbnail. Code is interchangeable; what changes is which GPIO numbers exist, and the canvas draws the board with Seeed's own pin labels so you wire against D0 to D10 as printed on the part.
- Processor
- ESP32-S3, dual-core Xtensa LX7 at 240 MHz
- Memory
- 512 KB SRAM · 8 MB PSRAM · 8 MB flash
- Emulation
- esp32s3js (in-browser)
- Languages
- Arduino C++ · MicroPython · ESP-IDF
- Plan
- Free
What you can do with the XIAO ESP32S3 simulator
The board on the canvas is the real thing as far as your code is concerned: the same pins, the same buses, the same peripherals, wired to the same 100+ sensors, displays and actuators every other Velxio board talks to.
Arduino C++ sketches
Write a sketch in the Monaco editor with library completion, compile it against the board's own Arduino core and run the real firmware binary. The Serial Monitor is the USB port.
MicroPython
Switch the board to MicroPython from the toolbar and run main.py against the same circuit. Drivers are plain .py files in the workspace, copied onto the board's filesystem before your script starts.
ESP-IDF projects
Build a full ESP-IDF project (v5.5.4) with FreeRTOS tasks, sdkconfig and components, and run it on the emulated chip without a devkit on your desk.
WiFi against a virtual access point
The emulator advertises the Velxio-GUEST network: HTTP servers, MQTT clients and NTP sync in your sketch connect and answer, without leaving the browser.
GPIO, PWM and ADC
Drive LEDs, relays and servos, read buttons and potentiometers, dim with PWM. Every pin follows the board's real pin map, so what works here works on the hardware.
I2C, SPI and UART
Talk to OLEDs, IMUs, ADCs, RTCs and SD cards over the buses the board really has. Bus traffic runs through emulated peripherals, not through a shortcut.
XIAO footprint
The thumbnail-sized XIAO pinout: D0 to D10 with the I2C, SPI and UART pads where every XIAO has them, so projects move between XIAO boards with a pin map check.
SPICE analog parts
Op-amps, transistors, regulators and passives simulate in real time with ngspice in the browser; the board's pins drive them and read the solved voltages back.
XIAO ESP32S3 examples
This board has no examples of its own yet. These are written for the ESP32-S3 DevKit devkit, which uses the same chip: they run on the XIAO ESP32S3 after a pin map check.
ESP32-S3 Blink LEDBlink an external red LED on GPIO4 of the ESP32-S3 DevKitC-1. Verifies ESP32-S3 GPIO emulation is working.
ESP32-S3 Serial EchoESP32-S3 reads from Serial and echoes back. Demonstrates UART and Serial Monitor integration on the S3.
ESP32-S3: SSD1306 OLED DisplayDisplay text on a 128×64 SSD1306 OLED over I2C from the ESP32-S3 (default Wire pins SDA=GPIO8, SCL=GPIO9).
ESP32-S3: Potentiometer (ADC)Read a potentiometer with the ESP32-S3 12-bit ADC on GPIO1 (ADC1_CH0) and print the raw value and voltage.
Related simulators
Frequently asked questions
- Can I run ESP32-S3 DevKit sketches on the XIAO ESP32S3?
- Yes, after a pin map check. The chip and the Arduino core are the same; the XIAO exposes eleven GPIOs plus the buses, so a sketch that used a pin the XIAO does not bring out needs to move it.
- Is WiFi emulated on the XIAO ESP32S3?
- Yes. The emulator advertises the Velxio-GUEST access point, so WiFi.begin connects, HTTP servers answer and MQTT clients publish, all inside the browser.
- What is the difference from the XIAO ESP32S3 Sense?
- The Sense adds the expansion board with a camera, a PDM microphone and a microSD slot. This page is the plain XIAO ESP32S3; the Sense has its own simulator page.
- Is the XIAO ESP32S3 simulator free?
- Yes. The XIAO ESP32S3 runs on the free plan: open the editor, place the board and press Run. No install and no account are needed, and Velxio's editor and simulator core are open source under the GNU AGPLv3.
- Which languages can I use on the XIAO ESP32S3?
- Arduino C++, MicroPython, ESP-IDF. The language is switched from the toolbar; the circuit on the canvas stays the same.
Ready to simulate the XIAO ESP32S3?
Open the editor, place the XIAO ESP32S3 from the picker, wire what you need and press Run.
Launch the XIAO ESP32S3 simulator →