Nothing leaves your computer
The OpenCascade CAD kernel runs in your browser as WebAssembly and reads the file there. No upload, no account.
IGES Viewer for .igs and .iges Files
Open IGES files from CATIA, NX, SolidWorks or Rhino in your browser. See surfaces and solids, check size and watertightness. Nothing uploaded.
Loading 3D preview
Drag to rotate
Open a file to see its size, triangle count and whether it is watertight.
Opened in your browser. Files are never uploaded.
Continue with your IGES file
Convert it for printing, or open another CAD format.
How to open an IGS file online
Open the file, turn it around, then check whether its surfaces close into a solid.
- 1
Open the IGS file
Drop an .igs or .iges file, or several at once. The CAD reader loads the first time you open one.
- 2
Rotate and inspect
Drag to orbit and scroll to zoom. Show the colors saved in the file, or the triangle wireframe.
- 3
Check and download
Read the size and the watertight result, then save the model as an STL for printing.
Why use this IGES viewer
See what is inside an IGES file before you send it to CAM, a slicer or a client.
Surfaces and solids
Trimmed NURBS surfaces and B-rep solids both open, so surface-only exports display too.
Real size
The unit is taken from the file's global section, and the size shows in millimeters or inches.
Watertight check
Shows whether the surfaces close into a solid. Surface exports often leave gaps a slicer has to bridge.
Colors and names
Entity colors and names saved in the file come through, and each solid or shell is its own object.
Wireframe view
See how finely the surfaces were split into triangles for display and for printing.
What's inside an IGS file
IGES, the Initial Graphics Exchange Specification, is the oldest neutral CAD format still in daily use.
A standard from 1980
IGES was first published in 1980 to move drawings and models between CAD systems. Version 5.3 from 1996 was the last, and newer work moved to STEP.
Fixed 80-column text
An IGES file is plain text in 80-character lines, split into Start, Global, Directory Entry and Parameter Data sections, each line tagged with its section letter.
Often surfaces, not a solid
Many CAD programs write IGES as separate trimmed surfaces. They look solid on screen but do not share edges, unlike a solid saved as entity type 186.
Units in the header
The global section stores a unit flag, from inches and millimeters to meters, and this viewer converts it to millimeters.
Who still works with IGES
IGES is old, but plenty of tools and archives still read and write it.
CNC and mold shops
CAM programs commonly accept IGES surfaces. Check what a customer sent before you plan the job.
Legacy design archives
Decades of parts were saved as IGES. Open an old file on any computer, without the program that made it.
Surface modelers
Rhino and Alias users trade freeform surfaces as IGES. Preview the shape and colors before you import it.
3D printing
Check whether an IGES model is closed, then convert it to STL for your slicer.
IGES viewer questions
Answers about IGS files, privacy, gaps, STEP and printing.
What is an IGS file?
An .igs or .iges file is a 3D CAD model in IGES, a neutral text format that CAD, CAM and surface modeling programs use to exchange curves, surfaces and solids with their exact geometry.
How do I open an IGS file without CAD software?
Drop it onto this page. The viewer runs in any modern browser on Windows, macOS, Linux and ChromeOS, with no install and no sign-up.
Is my IGES file uploaded?
No. OpenCascade, the open source CAD kernel, runs in your browser as WebAssembly and reads the file there. Only the reader itself is downloaded, once.
Why does it say my IGES model is not watertight?
Many IGES files are a set of separate surfaces rather than a closed solid, so neighboring faces do not share edges and leave tiny gaps. Export a solid (IGES type 186) or a STEP file from your CAD program, or let the slicer repair small gaps.
What is the difference between IGES and STEP?
Both carry exact CAD geometry. IGES dates from 1980 and is mostly used for surfaces; STEP is the newer ISO standard and stores solids, assemblies, names and colors more reliably. When you have the choice, ask for STEP.
Can I 3D print an IGES file?
Common slicers do not open IGES, so convert it to a triangle mesh first. Click Download STL here, or use the IGES to STL converter for batches and separate parts.