Velxio is a fully local, open-source multi-board emulator that runs in your browser. Developers can write Arduino C++ or Python code, compile it, and simulate it with real CPU emulation across 19 boards including Arduino Uno, ESP32, and Raspberry Pi Pico.

No installation required — just open velxio.dev and start coding. The platform supports 5 CPU architectures: AVR8 for classic Arduinos, ARM Cortex-M0+ for RP2040 boards, RISC-V for ESP32-C3 and CH32V003, Xtensa for ESP32 via QEMU, and ARM Cortex-A53 for Raspberry Pi 3. Each board runs with accurate timing and full GPIO support.

With 48+ interactive electronic components like potentiometers, sensors, and displays, developers can test circuits without hardware. The Monaco Editor provides syntax highlighting and autocomplete, while the compilation console shows real-time output. Multi-board simulation lets you run different architectures simultaneously — like Raspberry Pi 3 and Arduino communicating via serial on the same canvas.