Esp32sim runs ESP32 firmware in a browser without physical boards

The esp32sim project offers a browser simulator that its developers say boots real ESP32 ROMs, bootloaders and unmodified application images. It models four ESP32 chips across Xtensa and RISC-V processor architectures, giving firmware developers a way to run projects without physical boards. The code uses the MIT license. The browser version runs through WebAssembly, with demonstrations including display panels and ESP32-C3 and C6 firmware. The developers report real-time operation for several demos in Chrome. Browser networking lacks the host-socket access available in the command-line version. Hardware comparisons also have limits: trace checks normalize exceptions and resynchronize delay loops rather than establish uninterrupted cycle-by-cycle agreement.