STP · CAD Viewer
Free STP File Viewer
Someone sent you a .stp file and nothing on your machine will open it? Drop it here. It renders in seconds — no SolidWorks licence, no install, no account, and the file never leaves your browser.
No STP handy?
About the STP viewer
- Opens .stp files (and the identical .step extension) exported by SolidWorks, Fusion 360, Inventor, CATIA, Creo and Onshape.
- No CAD seat required — the solid is tessellated locally by an OpenCascade WASM engine, so a supplier part can be reviewed on any laptop.
- Nothing is uploaded, so confidential or NDA-covered parts stay on your machine.
- You get the part list from the file (hide or isolate any part), the original part colors, a Section tool that cuts the part along X, Y or Z to show walls and internal parts, and a two-point Measure tool that reads in millimeters — enough to check a supplier part's overall size, a clearance or a wall thickness.
- Not included: the feature history, GD&T / tolerance annotations, and hole-diameter or angle measuring.
- Once you can see it, convert the .stp to STL for printing or to OBJ/GLB for downstream tools below.
Frequently asked questions
- How do I open a .stp file without CAD software?
- Drop the .stp file into the box above. Flip3D tessellates and renders it in the browser — drag to rotate, scroll to zoom. No SolidWorks, Fusion or Inventor licence needed.
- Is this STP file viewer really free?
- Yes — free, no signup, no watermark, no trial window. Files up to 200MB open with no paid tier.
- Is .stp the same as .step?
- Yes. Both are the ISO 10303 STEP exchange format; the three-letter .stp exists because older Windows tools expected three-character extensions. This viewer accepts either.
- Does the .stp file get uploaded anywhere?
- No. There's no server and no upload — the file is read and rendered on your own device, then discarded when you close the tab.
- Can I measure or edit the part here?
- You can measure: click Measure, then two points on the part, and read the distance and X/Y/Z offsets in millimeters. Click Section to cut the part along X, Y or Z and see inside; measuring across the red cut face gives a wall thickness. You can also hide or isolate parts from the parts list. Editing isn't possible in a viewer — convert the .stp to a mesh and resize it in the free STL Editor, or check it in the 3D Print Checker.
- How do I turn a .stp file into an STL?
- Use the STP to STL converter — same engine, but it exports a printable mesh. It runs in the browser too, so nothing is uploaded.