Firmware runs on the printer’s control board and turns G-code into motor steps, heater control and safety checks. Updates from the maker can fix faults or add features; they are worth installing when the release notes address something relevant, following the maker’s instructions.
Between the slicer’s file and the printer’s motors sits firmware, which decides how instructions become movement and heat.
What firmware does
It reads G-code line by line. It drives the motors with the steps and accelerations configured for the machine. It controls heaters and fans to hold temperatures. It runs safety checks such as thermal runaway protection. It handles features like levelling, filament sensors and displays.
Types of firmware
Many printers run open firmware families configured by the maker; others run proprietary firmware. Some systems split the work between the printer board and a separate computer. The maker states which its printer uses.
When to update
Read the release notes. Updates that fix a fault you have, improve safety or add a needed feature are worth installing. The maker’s update procedure should be followed exactly, because an interrupted update can leave a board unusable.
After an update
Profiles may need adjusting and some settings may reset. A test print with a known file confirms the printer still behaves as before.
Questions makers ask before buying
What is thermal runaway protection?
A firmware safety check that stops heating when a temperature reading does not respond as expected, for example if a sensor comes loose. Makers list it among firmware features.
Can firmware updates be declined?
On many printers, yes. Some cloud-connected printers push updates automatically, and their makers describe how updates are handled.
Last reviewed 15 September 2026