STEP file viewer
Open a .step or .stp file in 3D in your browser, with no CAD software and no account. Look through an assembly part by part, check the size and the units it was drawn in, measure it, cut a section, and see what it costs to 3D print. Your file is deleted as soon as it's converted.
Drag to turn, scroll or pinch to zoom.
Parts in this file
Untick a part to hide it.
Your part
This part is under 10 mm across. STL and OBJ files have no units, so if it was drawn in inches it's 25.4 times bigger than shown: re-export it in millimetres.
Will it fit your printer?
| Printer | Build volume (mm) | Your part |
|---|
“Turned diagonally” means it fits at an angle on the bed. “On its side” means it fits if you lay it another way up, which can change how it prints.
How the STEP viewer works
- Conversion. Browsers can't draw STEP's exact surfaces, so our server turns them into a fine triangle mesh and sends it back to you. Most files take a few seconds; big assemblies take longer. The file and the mesh are then deleted.
- Assemblies. Parts keep the names and colours from the CAD model. Untick a part in the parts list to hide it and see what's inside.
- Units. STEP files record their units. We read them, convert inches, centimetres or metres to millimetres, and tell you which units the file was drawn in, with the CAD program that wrote it.
- Tools. View the part from the front, top or side, show its edges, cut across its width, depth or height, measure between any two points, save a picture, or save the part as an STL.
- Volume and price. We measure the part's volume, which is what sets a print's price: a one-off £7.50 setup fee per part plus the printing cost, for one copy with 3-4 days turnaround and free collection from Dalston, without supports. Orders start at £30 of printed parts. The filament weight is for PLA at 15% infill.
- Fit. We compare the part with 11 common home printers, turned diagonally and laid on each side. We print parts up to 330 mm; up to 180 mm in each direction gets an instant price.
STEP or STL for 3D printing?
Send the STEP if you have it. A slicer needs triangles, so an STL is already an approximation of your part, and its numbers have no units. From a STEP file we work from the part's real shape, in the units you drew it in. More on each format in STL, STEP or 3MF. Mesh files open in the STL viewer and cost calculator. If a slicer or another service asks for STL, press Save STL above the 3D view, or use the STL converter, which also takes 3MF, OBJ and GLB files.
Questions
How do I open a STEP file without CAD software?
Drop it into the viewer above. It opens .step and .stp files in your browser, on a phone or a computer, with nothing to install and no account. You can turn and zoom the model, look at it from the front, top or side, measure between two points and cut through it.
What is a STEP file?
STEP (ISO 10303, saved as .step or .stp) is the standard format for passing solid 3D models between CAD programs such as SolidWorks, Fusion, Inventor, Onshape and FreeCAD. Unlike an STL, it keeps exact curved surfaces and the units the part was drawn in, and one file can hold a whole assembly.
Can I view a STEP assembly?
Yes. Every part appears in the parts list with its name from the CAD model, and you can hide parts to see the ones inside. The size and price are for everything in the file together; to print parts separately, upload each one on the quote page.
Do you keep my STEP file?
No. Browsers can't read STEP files, so we convert yours into a 3D mesh on our server, send the mesh back to your browser and delete both straight away. Nothing is stored and no quote is created.
Why is my part the wrong size?
STEP files store their units, and we convert inches, centimetres and metres to millimetres. The viewer shows which units the file was drawn in. If the size still looks wrong, check the units in your CAD program's export settings.
How much does it cost to 3D print a STEP file?
Each part has a one-off £7.50 setup fee, plus the printing cost, which comes from the part's measured volume. The viewer shows the price for one copy in PLA or PETG; the quote page adds quantities, colours, supports and delivery.
What is the largest STEP file I can open?
Up to 30 MB here. Bigger files can still be priced: upload them on the quote page, which takes files up to 100 MB.