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
Ready-to-run projects for this board from the gallery. Open one, read the sketch, press Run.
XIAO Sky Duel: side-view dogfight (ILI9341 handheld)A biplane dogfight on a Seeed XIAO ESP32-S3 wired like a handheld console: an ILI9341 320x240 TFT, a four-button D-pad and A/B buttons. Point the D-pad where you want to fly; climbing costs speed, diving gains it, and a plane that gets too slow stalls. Shoot down the red squadron with A, bomb the flak guns and trucks with B, and survive the waves over a world four screens wide that wraps around, with parallax clouds and hills and a radar of the whole sky. The whole frame is drawn in a 150 KB buffer and sent in one SPI transfer. An attract-mode demo flies itself until you press a button. On a computer, play with the arrow keys, Z for A and X for B.
XIAO Quest: a tiny RPG with turn-based battles (ILI9341 handheld)A top-down RPG on a Seeed XIAO ESP32-S3 with an ILI9341 TFT and console buttons. Walk the village, the forest and a dark cave tile by tile; talk to the elder for the gate key, buy potions from the merchant, heal at the fountain and open chests for a sword and a ring. Random encounters lead to turn-based battles (attack, fire spell, potion, run) with experience and level ups, and the Shade King waits at the end of the cave. Tiles are drawn by code at boot and the hero carries a light in the cave. An attract-mode demo walks and fights on its own. On a computer, play with the arrow keys, Z for A and X for B.
XIAO Gear Hop: side-scrolling platformer (ILI9341 handheld)A side-scrolling platformer on a Seeed XIAO ESP32-S3 with an ILI9341 TFT and console buttons. A little robot runs and jumps through two levels collecting gears: hold A to jump higher, hold B to run, stomp beetles and drones, avoid spikes, bump ? blocks from below and ride moving platforms over the wide gaps to the flag. Tile collisions, coyote time, a jump buffer and two parallax layers of hills, all drawn into a full frame buffer. An attract-mode demo runs the levels by itself. On a computer, play with the arrow keys, Z for A and X for B.
XIAO Circuit Defense: tower defense with BFS pathfinding (ILI9341 handheld)A tower defense game on a Seeed XIAO ESP32-S3 with an ILI9341 TFT and console buttons. Bugs crawl across a circuit board toward the chip; build LEDs that fire a laser, capacitors that discharge into everything around them and coils that slow bugs down, and upgrade them as the waves get harder. The bugs always take the shortest route, found with a breadth-first search that runs again after every build and is drawn as a copper trace; you can reroute them but never wall them off. An attract-mode demo builds and defends on its own. On a computer, play with the arrow keys, Z for A and X for B.
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 →