Free Online NC File Viewer
Open an .nc program on this page and see the toolpath of your CNC job in 3D: the moves of the cutter, their size and shape, before the machine runs it.
- Free
- No sign-up
- No install
Open Files → see the toolpath in 3D
What you can do with your NC 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 an NC file in 3 steps
Open your NC file
Click Open Files in the viewer above, then Browse… and pick your .nc 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.
NC viewer FAQ
What program opens .nc files?
An .nc file is usually a CNC program in G-code. MeshInspector opens it on this page and in the free desktop app for Windows, macOS and Linux and draws the toolpath in 3D. A text editor opens it too, but only as lines of code. Some .nc files hold NetCDF science data instead; those are not G-code.
How do I open an NC file online?
Click Open Files in the viewer at the top of this page, then Browse… and pick your .nc file. It opens as G-code, and the toolpath appears in 3D. You need no sign-up and no install, and the file is not uploaded to a server: it is read in your browser.
Can I edit or simulate the NC program here?
No. This page shows the toolpath so you can check it; it does not edit the code or simulate the cut. Change the program in your CAM software or in a text editor, then open the new file here again and compare the path with what you expect before the machine runs it.
Is the NC file viewer free?
Yes. Viewing NC files 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 a toolpath does not need them.
What is the difference between NC and G-code files?
Usually none: .nc is one of the extensions of G-code programs, like .gcode, .tap or .ngc. The content is the same kind of text, commands such as G0 and G1 with coordinates. MeshInspector opens .nc and .gcode files the same way, as G-code, and draws their moves as a toolpath.
Add an NC 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.
