Serial Monitor

A free browser-based serial monitor for USB devices like the RP2040 boards used in our builds. No drivers or software to install — it runs directly in your browser via the Web Serial API.

How to Use the Serial Monitor

  1. Plug your USB device (RP2040, Arduino, ESP32, etc.) into your computer.
  2. Click Connect and select the matching port from the browser's prompt.
  3. Set the baud rate to match your device's firmware — CircuitPython's serial console defaults to 115200.
  4. Watch incoming data appear in the terminal, or type into the input box and press Enter to send.
  5. Use the Ctrl+C button to interrupt running code, or Ctrl+D to soft-reboot the board — handy when working with a CircuitPython or MicroPython REPL.

Is My Data Sent Anywhere?

No. This tool runs entirely in your browser — the serial connection is made directly between your browser and your USB device using the Web Serial API. Nothing you send or receive passes through our servers.

Building one of our kits? Check out the Mighty Mini Macro Pad or Mighty Mini Media Controller build guides, then come back here to watch its serial output while you flash firmware.