---
title: ".gcode file — what it is and how to open it"
description: "A .gcode file is a G-code Toolpath. The line-by-line instructions a 3D printer or CNC machine actually executes. How to open one on Windows, macOS and Linux, and what to convert it to."
url: https://atoneplace.net/file/gcode/
site: "At One Place"
---

# .gcode files

**.gcode file: G-code Toolpath**

The line-by-line instructions a 3D printer or CNC machine actually executes.

## What opens a .gcode file

- **Windows:** PrusaSlicer / Ultimaker Cura (preview), Notepad (built in), Pronterface
- **macOS:** PrusaSlicer / Ultimaker Cura (preview), TextEdit (built in)
- **Linux:** PrusaSlicer / Ultimaker Cura (preview), Text Editor (built in), OctoPrint
- **In a browser:** gcode.ws viewer

## What a .gcode file is

G-code is plain text telling a machine where to move, how fast, and at what temperature — the output of a slicer, not a model. It is specific to the printer and settings it was generated for, so a file sliced for one machine can damage another. Any text editor opens it, and slicers and preview tools such as gcode.ws show the toolpath layer by layer.

## Converting it

A .gcode file is commonly converted to .txt. It is a plain text format, so any text editor can open and edit it directly.

## Details

- **Extension:** .gcode
- **Full name:** G-code Toolpath
- **Category:** 3D and CAD
- **Created by:** RS-274 / machine tool standard
- **Format:** Plain text

## Common questions

### How do I open a .gcode file?

On Windows use PrusaSlicer / Ultimaker Cura (preview); on macOS use PrusaSlicer / Ultimaker Cura (preview); on Linux use PrusaSlicer / Ultimaker Cura (preview). The line-by-line instructions a 3D printer or CNC machine actually executes.

### What is a .gcode file?

G-code Toolpath. G-code is plain text telling a machine where to move, how fast, and at what temperature — the output of a slicer, not a model. It is specific to the printer and settings it was generated for, so a file sliced for one machine can damage another.

### Can I convert a .gcode file?

Yes. It is usually converted to .txt, either by exporting from one of the programs listed above or with a format converter.

## Related pages

- [.stl — Stereolithography Model](https://atoneplace.net/file/stl/)
- [.obj — Wavefront OBJ Model](https://atoneplace.net/file/obj/)
- [.fbx — Filmbox 3D Scene](https://atoneplace.net/file/fbx/)
- [.blend — Blender Project](https://atoneplace.net/file/blend/)
- [.3mf — 3D Manufacturing Format](https://atoneplace.net/file/3mf/)
- [.3ds — 3D Studio Model](https://atoneplace.net/file/3ds/)

## Sources

- Media Types Registry — IANA (https://www.iana.org/assignments/media-types/)
- Official vendor product documentation — At One Place (/about/)