I can't speak for a JS virtual machine, but for a point of comparison CircuitPython[1] runs on many ESP32 boards and builds are often under 1.5 MB. It does come

I can't speak for a JS virtual machine, but for a point of comparison CircuitPython[1] runs on many ESP32 boards and builds are often under 1.5 MB. It does come with a whole set of modules, with the ones you'd expect to have in Python like "re" or "time" (although they only have a few functions in there), but also with CircuitPython-specific modules like "board" or "digitalio" to access peripherals, or "wifi" for networking. The boards listed on the CircuitPython downloads page usually have between 2 and 8 MB of flash, so you often have enough for the VM and your own code plus a few files. [1] https://circuitpython.org/ https://circuitpython.org/