G-code: what it is and why not to send it
G-code is a list of commands for a printer or CNC machine that sets the movements, speed, temperature and amount of material. In 3D printing a slicer creates it from a 3D model.
No model? No problem, pick a ready one
These sites have thousands of free models. Download an STL or 3MF and upload it here. If you sell it or use it for business, check the model licence. How to pick a model and licence
What G-code is
G-code was created for numerically controlled machines such as mills and lathes. It came into 3D printing mainly through the RepRap project, which many of today's printers descend from. It is a text file with thousands of lines, for example "G1 X10 Y20 E0.5", which means move to that position and extrude a little material on the way.
G-code is not a 3D model. It is a finished set of instructions for one specific type of printer with a specific nozzle, material and settings. A slicer creates it from a model in STL, 3MF or a similar format.
Why we do not accept G-code from customers
We always prepare the model for printing ourselves, on our server and with the settings for our printers. That is the only way we can guarantee the price, the delivery date and the quality. G-code prepared for a different printer could have the wrong temperature, speed or build plate size, and the print would fail.
You also cannot reliably get a model back out of G-code. So please send the original file, not the slicer output.
What to send instead of G-code
- A single-colour part: STL, OBJ or STEP.
- Several colours: 3MF, which remembers which part has which colour.
- If you only have the G-code: try to get the original model from whoever sent you the G-code, or from the site you downloaded it from.
After you upload the model, we prepare it for printing with a layer height of 0.2 mm and an infill matching the strength you choose. The price and the delivery date then come from the exact grams and print time.
Common questions
Can I send you a .gcode or .bgcode file?
No, we do not accept G-code. Send the model as STL, 3MF, OBJ or STEP and we will prepare it for printing ourselves.
Can G-code be converted back to STL?
Only very roughly and with errors. It is much better to find the original model.
Why won't you print my G-code if it works on my printer?
It is prepared for your printer, nozzle and material. Our printers need their own settings, otherwise we could not guarantee the result or the price.
Related terms
Slicer
A slicer is a program that cuts a 3D model into thin layers and works out the nozzle path for each one. The result is G-code for the printer and exact figures for material use and print time.
STL
STL is the most common file format for 3D printing. It describes only the surface of a model as a mesh of triangles, with no colours, material or units.
3MF
3MF is a 3D printing file format that carries units, colours, materials and several parts as well as the shape of the model. It succeeds STL and is the best choice for multicolour printing.
FDM
FDM is a 3D printing technology where the printer melts plastic filament and lays it down through a nozzle layer by layer. It is the most widespread and cheapest way to 3D print.
Layer height
Layer height is the thickness of a single layer, from which the printer builds the part from the bottom up. It affects how visible the layers are on the surface and how long printing takes.
SourcesSources checked 1 November 2026, 2
We will print it for you
Upload a model and see the price per piece, the total with shipping and the date at once. We print in Košice, Slovakia, from PLA and PETG.
No model? No problem, pick a ready one
These sites have thousands of free models. Download an STL or 3MF and upload it here. If you sell it or use it for business, check the model licence. How to pick a model and licence