View NC files in your browser
The G-code of mills, routers and lathes, from Fusion, Mastercam, Vectric and every CAM app. Open a program right here and see its toolpath before you cut. Nothing leaves your device.
Or drop it anywhere on this page
What you'll see
Your program opens in 3D as the machine will move, its cuts by tool and its rapid moves apart, with its tools beside it.
- The slider • Run the program move by move
- Each tool in its color • Hide the rapid moves
- Inspect • Cutting time, path length and moves
- Export • Save the view as PNG
About NC
NC programs are G-code for machines that cut: mills, routers, lathes, plasma and laser cutters. CAM apps like Fusion, Mastercam, Vectric and FreeCAD write them for controllers like LinuxCNC, Mach3, Haas and GRBL, as .nc, .ngc, .tap or .cnc files.
Each line moves the tool: G0 at full speed above the work, G1 cutting in a straight line at its feed rate, G2 and G3 in arcs. Tool changes, spindle speeds and canned cycles, like G81 for drilling, fill out the program.
Filepeek reads it in your browser and draws the toolpath in 3D: each tool's cuts in its color, the rapid moves apart and each drilling cycle as its hole. Drag the slider to run the program move by move, hide the rapids, and see each tool's path and the cutting time at its feed rates.
CNC program
.nc • .ngc • .cnc • .tap
Format
- MIME type
- text/plain
- Made by
- The EIA, as RS-274
- Released
- 1963
Inside the file
- Moves
- G0 rapids, G1 cuts, G2 and G3 arcs
- Tools
- T and M6, with the spindle's speed
- Cycles
- G81 to G83 for drilling
- Units
- Millimeters with G21, inches with G20
Opens in every browser
Browsers show NC programs as text or download them. Filepeek opens them in 3D in Chrome, Edge, Firefox and Safari, on any device.
- YouChromeOpens through Filepeek
- YouEdgeOpens through Filepeek
- YouFirefoxOpens through Filepeek
- YouSafariOpens through Filepeek
Questions
How do I view an NC file?
Drop it on this page or press Peek an NC. The toolpath opens in 3D, each tool in its color, with nothing to install.
Can I run it move by move?
Yes. Drag the slider under the toolpath to show the program as far as any move, or press Play to watch it run. The arrow keys step it on.
Does it read programs in inches?
Yes. A program that sets G20 reads in inches, and one that sets G21, or nothing, in millimeters.
Does it show the material cut away?
No. It draws the path the tool takes, which shows what the program cuts and where it goes, without carving a block of stock.
Is my file uploaded?
No. The program opens inside your browser and never leaves your device.