3D Printing

Klipper update checklist (host, MCU, and config changes)

Klipper updates come in two halves: the host software and the micro-controller firmware. Here's the order that avoids a printer stuck in a version-mismatch error.

2026-10-20
Illustration: Klipper update checklist (host, MCU, and config changes)
Original illustration by SafeToUpdate (CC BY 4.0).

Klipper doesn’t do traditional releases for most users. You update from the Git repository, usually through Moonraker’s update manager in Mainsail or Fluidd. That makes reading the changes your job.

1. Read Config_Changes first

Klipper’s own FAQ says the first step of any upgrade is reviewing the config changes document. It lists every change that isn’t backwards compatible, newest first. Examples from recent months: a removed TEMPERATURE_PROBE_CALIBRATE METHOD=tap parameter (2026-09-15) and corrected PID_CALIBRATE math (2026-10-18). Search your printer.cfg and macros for anything mentioned.

2. Back up your config

Download the whole config folder from Mainsail/Fluidd, or commit it to Git. Include printer.cfg, included files, and macros.

3. Don’t update mid-print

Update with the printer idle and heaters off. Updating Klipper restarts the host service.

4. Update the host software

Use the update manager in Mainsail/Fluidd (Moonraker update_manager) or, per the Klipper FAQ:

cd ~/klipper
git pull
sudo service klipper restart

5. Reflash the MCU when Klipper asks

If Klipper reports that the micro-controller needs reflashing (or a version mismatch), rebuild and flash, as the FAQ describes:

cd ~/klipper
make menuconfig     # confirm settings match your board
make clean && make
sudo service klipper stop
make flash FLASH_DEVICE=/dev/serial/by-id/<your-device>
sudo service klipper start

Use the /dev/serial/by-id/ path rather than /dev/ttyACM0, which can change. Boards that don’t support make flash need their own method. See the board’s sample config and the Installation guide. Remember every MCU: toolhead boards, CAN boards, and the host MCU if you use one.

6. Verify before a real print

Home all axes, heat the bed and nozzle, and check klippy.log for warnings. If the changelog touched probing or PID, re-run that calibration. Note that RESTART and FIRMWARE_RESTART don’t load new code. Only a service restart and a reflash do.

Checklist

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