Free Online G-code Viewer
Open a G-code file on this page and see its toolpath in 3D: the moves of the printer nozzle or the cutter, with their size and shape, before you run the job.
- Free
- No sign-up
- No install
Open Files → see the toolpath in 3D
What you can do with your G-code file
See the toolpath in 3D
The moves of the program are drawn as lines in 3D, so you see the path of the nozzle or the cutter before you run the job.
Check it from every side
Turn and zoom the path with the mouse or touchpad. Fit Data brings the whole program back into view.
Check the size
Bounding Box draws the extent of the moves, and the Information panel shows their size along X, Y and Z.
Open .gcode, .nc and .txt
G-code from slicers and CAM software opens in one viewer: .gcode, .nc and .txt files all open as G-code.
How to open a G-code file in 3 steps
Open your G-code file
Click Open Files in the viewer above, then Browse… and pick your .gcode file. It opens as G-code in your browser, with no account and no install.
See the toolpath in 3D
The moves of the program appear as a 3D path. Drag to turn it, scroll to zoom, and click Bounding Box to see its size.
Fix it and check again
If the path is wrong, change the program in your slicer or CAM software and open the new file here again. More toolpath tools are in the desktop app.
G-code viewer FAQ
How do I view a G-code file online?
Click Open Files in the viewer at the top of this page, then Browse… and pick your .gcode file. MeshInspector draws the toolpath in 3D right in your browser: no sign-up, no install, and the file is not uploaded. Turn and zoom the path to check it from every side.
Which files does this G-code viewer open?
It opens .gcode, .nc and .txt files as G-code: the plain-text programs that slicers write for 3D printers and CAM software writes for CNC machines. The moves of the program are drawn as lines in 3D, and Bounding Box shows the size of the whole path along X, Y and Z.
Is the G-code viewer free?
Yes. Opening and viewing G-code on this page is free and needs no account. The desktop MeshInspector app is free on the Community plan as well. Its G-code processing tools, such as Tool Path and G-code to Lines, belong to the paid Professional plan; viewing the path does not need them.
Does it simulate the machine or estimate print time?
No. This viewer shows where the nozzle or the cutter moves, so you can check the shape and the size of the path before you run the job. It does not simulate material removal and does not estimate print time; your slicer or CAM software shows those numbers for the same file.
What is G-code?
G-code is the plain-text language of CNC machines and 3D printers. Each line is a command, for example G0 for a rapid move or G1 for a cutting or printing move, with the X, Y and Z coordinates to go to. Slicers and CAM programs write it, and machines run it line by line.
Add a G-code Viewer to Your App
- Multi-Format Support — meshes, point clouds, voxels, and line data
Modern UI — built with Dear ImGui: ribbon interface, scene tree, view cube, and measurement tools.
Order-Independent Transparency (OIT) — realistic rendering of transparent materials.
Customizable Interaction — support for mouse, keyboard, touch gestures, and SpaceMouse devices.
Plugin Architecture — extend the Viewer with your own tools and workflows.
