Klipper Explained — What It Is and Whether You Need It
The firmware behind most fast printers, in plain English. What it changed, why the Openness score cares, and when it does not matter.
If you have read more than a couple of printer reviews you have seen the word "Klipper", usually as a selling point. Here is what it is, and whether you should care.
What firmware does
Every printer runs firmware: the software that turns G-code — "move here, extrude this much, heat to 220 °C" — into precisely timed signals to motors and heaters. For years that meant Marlin, running entirely on a small microcontroller on the printer's mainboard.
What Klipper does differently
Klipper splits the job in two. A small, fast computer — a Raspberry Pi or something built into the printer — does the heavy maths, and sends precisely timed step instructions to the mainboard, which just carries them out.
Because the heavy lifting happens on a much more powerful processor, Klipper can do things that were impractical before:
- Input shaping. The printer measures its own vibration with an accelerometer and cancels it out, removing the ringing "ghost" lines that appear after sharp corners at speed. This is the main reason a $250 printer today outruns a $2,000 printer from 2019.
- Pressure advance. It predicts the pressure in the nozzle and adjusts extrusion on the fly, so corners stay sharp and lines stay even at high speed.
- Configuration in a text file. Settings live in a readable config file you can edit, instead of being compiled into firmware.
- A web interface. Mainsail and Fluidd let you upload, monitor and control prints from a browser on your local network, with no cloud involved.
Stock Klipper vs "Klipper-based"
This is the part the marketing skips. Many printers now say they run Klipper, but they differ a lot:
Stock Klipper with root access. You can edit the config, update from the open-source project, and install Mainsail, Fluidd and community add-ons. The Sovol SV08, Qidi Q1 Pro, Qidi Plus 4, Qidi X-Max 3 and a self-built Voron 2.4 all work this way.
A manufacturer's fork. The printer runs a modified Klipper with the manufacturer's own interface on top. It is often locked down by default, and root access ranges from simple to unsupported. Several Creality and Elegoo machines work like this.
Not Klipper at all. Bambu Lab and Prusa use their own firmware. Prusa's is open-source; Bambu's is not. Both get the same benefits — input shaping and pressure advance — without Klipper's flexibility.
This is a big part of what our Openness score measures. A printer running stock, rootable Klipper can be repaired, modified and kept updated by its community long after the manufacturer loses interest.
Do you need it?
Probably not, if you want a printer that works out of the box and you are happy with the manufacturer's software. A Bambu Lab A1 or P1S gives you everything Klipper gives most users, with far less fiddling.
Yes, if you like to tune and modify, you want local control without any cloud, you plan to add hardware such as toolhead cameras, filament sensors or multi-material units, or you simply want to be sure the printer is still yours in five years.
Can I add Klipper to my old printer?
Usually, yes. Almost any Marlin printer can run Klipper with a Raspberry Pi or a similar small board. It is a well-documented weekend project, and it can turn a slow older printer into a surprisingly fast one. Expect to spend a few hours on setup and calibration, and budget for the Pi and an accelerometer.