Serial monitor

Read the board’s log from this page and save it to a file. No terminal to install, no drivers to find, and nothing leaves your browser — the log is never uploaded anywhere.

Not connected.

Not at the board? Paste a log instead

A log somebody sent you, or one downloaded from the device (Settings → System → Download log). It gets the same colouring and the same Save button.



  

What to expect

  1. Connect the board to this computer with a USB cable.
  2. Press Connect and pick the board’s port. On Linux it is usually /dev/ttyACM0 or /dev/ttyUSB0; on Windows a COM port; on macOS a usbmodem or usbserial entry.
  3. The log appears as it arrives. Panics, warnings and the boot banner are coloured so they are findable in a long capture.
  4. Press Save to file and attach the file to your issue or discussion. That single file usually answers a question that would otherwise take a week of messages.

This page only listens. It never writes to the port, and it clears DTR and RTS as soon as the port opens — asserting those is what holds a board in reset or drops it into the ROM loader, and a monitor that did it would change the very thing you are trying to watch.

If the log is empty