How to open a STEP, STP, IGES or IGS file online
- Choose a .STEP, .STP, .STE, .IGS, .IGES, .SLDPRT, SolidWorks .prt, .3ds, .3dm or limited ASCII DXF from Files or Downloads (not Photos on a phone).
- The model opens in this tab. Nothing is uploaded.
- Orbit by dragging. Scroll or pinch zooms toward the pointer. A cross marks the center the view rotates around. Fit frames the whole part.
- Click a part on the model or in the parts list, then hide or show it.
- Turn on Measure. Length is two points (3D distance plus ΔX, ΔY, ΔZ). Diameter and radius read a circular edge or a round face, with a 3-point check when the circle is not an edge. Angle is two straight edges. Area is one click on a face, and the readout is that face’s mesh area in square millimetres. A tap that misses the solid is ignored. Use Clear to start again.
- Download saves a PNG of the view on screen.
Load the sample cube, or drop a customer STEP. For a hole, choose Diameter and click the circular edge or the bore wall. For a span or a thickness, choose Length. For an angle, click the two edges. That is how we check a bore against a quote before we program wire EDM. A projected drawing is made on the CAD to 2D DXF projections, then opened here.
What the viewer opens, and what the converter writes
This page opens a file and checks dimensions. It does not save a converted CAD file. The CAD Converter is the page that writes one. The table is the list for both.
| File | Viewer opens | Converter writes |
|---|---|---|
| .step, .stp, .ste | Yes. ISO 10303. One STEP file, three extensions. | Yes, from a .SLDPRT or from elementary IGES. One STEP file, three download names. The edges can also be written as DXF. |
| .igs, .iges | Yes. One IGES file, two extensions. This page is the IGES viewer. | Yes, from a .SLDPRT or from an elementary STEP solid. One IGES file, two download names. The edges can also be written as DXF. |
| .sldprt | Yes. This tab converts it to STEP, then shows the solid. | Input for STEP, IGES, or exact DXF edges. The output is not another .sldprt. |
| SolidWorks .prt | Yes, when the file is a SolidWorks part. Shown the same way as .SLDPRT. | No. The converter does not write a .prt file. |
| .3ds | Yes. 3D Studio mesh. Sizes are shown as millimetres. The file stores no unit. | DXF mesh only. The coordinates are written as millimetres. |
| .3dm | Yes, when a display mesh is already stored. Scaled to millimetres when the file records a unit. | DXF mesh only, when a display mesh is already stored. |
| .dxf | Yes. ASCII lines, circles, arcs, ellipses, polylines and 3D faces, scaled to millimetres when the file records a unit. Measure reads length, diameter, radius and angle on those curves. | Yes. Exact edges from STEP, IGES or .SLDPRT. A triangle mesh only from .3ds or Rhino. |
| Not these | Parasolid .x_t and .x_b, CATIA, Inventor, NX, JT, ACIS, Pro/ENGINEER, DGN, WMF, PDF, STL and OBJ. NX and Pro/ENGINEER .prt. A .3dm with no display mesh. Assemblies (.SLDASM, .ASM) and drawings (.SLDDRW). SPLINE, HATCH and INSERT entities inside a DXF. | The converter does not write Parasolid, CATIA, Inventor, NX, JT, ACIS, Pro/ENGINEER, DGN, WMF, PDF, STL, OBJ, .3ds, .3dm or .prt. It does write DXF. The weight calculator weighs STEP and IGES, and also a SolidWorks .SLDPRT or .prt, a .3ds mesh, and a Rhino .3dm that already has a display mesh. |
Hide parts, orbit and inspect assemblies
Quotes often arrive as a STEP, not a dimensioned drawing. Open it, hide the parts in the way, and check a span, a thickness, a diameter or an angle before wire EDM. This is for looking and measuring, not a certified scale reading. A sample cube is included so you can try it without a CAD export. Huge assemblies are limited by device memory — export a lighter file if the tab struggles.
STEP file viewer vs STEP weight calculator
Need the mass of one component, or of the whole model? Upload the file on the STEP file weight calculator and hide the parts you do not want. The weight is only the parts still shown. This viewer hides parts so you can see them, and Download saves a PNG, but it does not calculate mass. For plate, bar or tube from typed sizes, use the metal weight calculator. Convert millimetres to inches in the unit converter.
Open an IGES or IGS file
IGES is this same viewer, not a second address. .igs and .iges are one format. To weigh an IGES file, upload it on the STEP, STP, IGES & IGS weight calculator.