NC Viewer: Online & Free

Open NC files: visualize toolpaths, check the bounding box, measure distances and angles, and review layers before sending the job to your 3D printer or CNC machine.

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Which NC Viewer Is Best for You?

Compare popular NC viewers to find the best one for your 3D workflow.

MeshInspector
MeshInspector
Other STL Readers
Perfomance
Ultra-fast (GPU acceleration)
High
Slow
Batch Import
Unlimited
Unlimited
Single file
File Limits
Unlimited
Unlimited
~100 MB
Measurement Tools
Advanced
Advanced
Limited
Metadata Support
Full
Full
Not supported
Scaling
Advanced
Advanced
Not supported
3D Editor
Advanced
Advanced
Not supported
Screenshots
Advanced
Advanced
Limited
Supported Files
STL (ASCII/Binary), OBJ, PLY, GLTF
STL (ASCII/Binary), OBJ, PLY, GLTF
STL (Binary)
Export
Multiple formats
Multiple formats
Not supported
Security & Privacy
Corporate security + Local storage
SSL + Auto-delete
Server-side storage
Cross-Platform
Windows, macOS, Linux
All devices
Web only, poor mobile UX
Suitable for
Professional & industrial use
Quick viewing & sharing
Not recommended

Ready to get started with MeshInspector?

Join engineers, designers and makers who trust MeshInspector to inspect 3D models and NC toolpaths. Validate your parts and jobs with no limits and professional‑grade visualization.

How to Open LAS Files on Windows, Mac & Linux

Engineers and manufacturing professionals regularly employ various tools to open and assess NC files. These contain the machine instructions for milling, routing, drilling, engraving, and other subtractive workflows. Because NC code defines every movement, from rapid positioning to cutting paths, a viewer is to deliver accuracy, speed, and stable performance on any operating system. MeshInspector tackles this need by offering a free and cross-platform read NC file program. You can inspect toolpaths both offline through the downloadable application and online through the browser.

1

Opening an NC File

Under the ’Home’ tab, click ’Open Files.’ This option lets you load your NC file into the MeshInspector program for inspection. After you select the file, the viewer imports the complete toolpath and prepares it for visualization, regardless of how large your projects are or how many tool movements they contain.

2

Selecting an NC File

Click ’Browse.’ Navigate to the folder where your NC file is stored. Then either double-click the file or confirm the selection with Upload. The MeshInspector program for reading NC files can also open entire folders containing multiple operations, which is useful when a workflow is split into components.

3

Viewing an NC File

After the NC file is loaded, its toolpath appears in the viewport. You can inspect the machining trajectory from any angle. Rotation of the view is possible by dragging with the left mouse button or employing one-finger touchpad gestures. Pan the scene by holding the right mouse button or sliding two fingers on a touchpad. Zoom in or out with the mouse wheel or a pinch gesture. To tilt, hold Ctrl and drag with the left mouse button. These controls let you examine rapid positioning moves, cutting passes, vertical Z transitions, and the overall machining strategy represented in the NC program.

4

Checking Toolpath Extents

In the ’Inspect’ tab, you can activate ’Bounding Box’ or ’Show Dense Box’ to examine the spatial limits of your NC toolpath. Bounding Box outlines a simple axis-aligned frame that surrounds the selected motion path, giving you a clear overview of its overall footprint. Show ‘Dense Box’ computes a tight and geometry-aware envelope that follows the toolpath closely.

5

Measuring Angles on NCs

MeshInspector lets you analyze geometric relationships inside an NC with precision. To measure an angle, open the ’Measure Angle’ tool in the ’Inspect’ tab and select three points along the trajectory. After the third point is placed, the viewer immediately computes the angle and presents the result in both the viewport overlay and the measurement panel.

6

Aligning an NC Toolpath with 3-2-1 Align

The ’3-2-1 Align’ tool in the ’Transform’ tab helps you place an NC toolpath into a stable and predictable coordinate orientation. This method is widely used to define positioning through three sequential references, i.e., primary plane defined by three points, a secondary direction set by two points, and a final axis constraint determined by one point. In MeshInspector, this alignment workflow lets you correct programs exported with unexpected rotations or offsets.

Open-Source NC Viewer for Developers

Integrate real-time 3D visualization, mesh analysis, and measurement tools directly into your applications with MeshLib SDK.

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