STEP File Viewer – STP Viewer Online

Free STEP file viewer and STP viewer online. Open a .STEP or .STP in the browser — no install. Rotate, pan, zoom and click two points to measure. Files stay on your device.

Your file is processed locally in your browser. Nothing is uploaded to a server.

STEP / STP viewer

Drop a .STEP or .STP file to view it and check dimensions.

On a phone, open the file from Files or Downloads. The 3D model stays on this device. After it loads, click two points to check any dimension.

Size unit

How to open a STEP file

This is a free STEP file viewer and STP viewer online. Choose a .STEP or .STP from Files or Downloads — no SolidWorks, Inventor or desktop install, and the file is not uploaded. .STEP and .STP are the same ISO 10303 format; only the extension differs.

Example — open a file and check a hole

Load the sample cube, or drop a customer STEP. Orbit to the face with the hole. Click one point on the near wall, then the far wall: the readout is 3D distance plus ΔX, ΔY and ΔZ. That is how we check a bore against a quote before we program wire EDM.

Need mass from the same solid? Open the STEP model weight calculator. For plate, bar or tube, use the material weight calculator. Convert millimetres to inches in the unit converter.

How a toolroom uses a STEP model

Quotes often arrive as a STEP, not a dimensioned drawing. We open the file, orbit to the faces that matter, and click two points to check a hole, a span or a thickness before we program wire EDM. This viewer is for looking and measuring — not a certified scale reading.

In the browser

Open CASCADE tessellates the B-rep solid to triangles; Three.js renders it. Drag to orbit, right-drag or two fingers to pan, scroll or pinch to zoom. Double-click a face to set the pivot; Fit frames the whole part. On a phone, pick the file from Files / Downloads, not Photos. A sample cube is included so you can try it without a CAD export. Huge assemblies are limited by device memory — export a lighter STEP if the tab struggles. .STEP and .STP work today; STL, OBJ, DXF and IGES are not on this page yet.

Frequently asked questions

Is this an STP viewer online / STEP file viewer?+

Yes. It is an STP viewer online and a free STEP file viewer (also an online STEP viewer and online STP viewer). Open a .STEP or .STP file in the browser — no install, no account. The same engine is the STP file viewer and STEP viewer online.

How do I view a STEP file or open an STP file online?+

Use Choose file, then pick the .STEP / .STP from Files or Downloads (not Photos on a phone). The model tessellates in the tab. Orbit, pan, zoom, and click two points to measure. Nothing is uploaded.

Are my CAD files uploaded to a server?+

No. STEP parsing runs in WebAssembly inside your browser. The file never leaves your device. That is why large assemblies are limited by your computer’s memory rather than a network upload.

Which formats work today?+

STEP and STP (AP203/AP214 style files that Open CASCADE can tessellate). Use it as a STEP file viewer, STP file viewer, or STP file viewer online — same engine. The viewer is structured so STL, OBJ, DXF and IGES can be added later without changing the rest of the site.

Is this a free STEP viewer / online CAD viewer?+

Yes. It is a free STEP viewer and free STP viewer that runs as an online CAD viewer / 3D CAD viewer in the browser. Open a STEP file or open an STP file from Files or Downloads — nothing is uploaded and there is no install.

Why does a large STEP file take time?+

B-rep solids must be tessellated into triangles. Complex assemblies with tight tolerances take longer. Keep the tab in the foreground; a progress state is shown while the WASM engine works.

Can I measure or explode assemblies?+

Click (or tap) two points on the model to check a 3D distance plus ΔX, ΔY and ΔZ. Exploded views are not supported. For estimated weight from the same solid, open the STEP model weight calculator.

Why won’t a STEP file open on my phone?+

Phone photo pickers do not list CAD files. Use Choose file, switch to Files / Downloads, and select a .step or .stp document. If the file has no extension, the viewer still accepts it when the contents start with ISO-10303-21. Very large assemblies can run out of memory on a phone — export a simpler STEP from CAD if that happens.

How do I check a dimension on the model?+

After the file loads, click (or tap) two points. Measuring is on by default. The tool snaps to a nearby corner of the tessellated face when you are close, then shows the 3D distance plus ΔX, ΔY and ΔZ. Drag to orbit; a click that misses the solid is ignored. Use Clear to start again.

The model looks off-centre and I cannot re-focus it+

Use Fit to frame the whole part. Double-click (desktop) or double-tap (phone) a face to put the orbit pivot on that point, then drag to rotate around it. Pinch or scroll zooms toward the cursor; two-finger drag or right-drag pans.

Do I need CAD software or a STEP file reader installed?+

No. This is a free program to open STEP files in the browser — a STEP file reader and STP file opener without SolidWorks, Inventor or a desktop install. Choose the .STEP / .STP from Files or Downloads; the tessellator runs in the tab.

Is there a free STP file viewer download?+

You do not download a desktop STP viewer. This is a free STP file viewer and free STEP viewer that runs in the browser — no installer, no account. Searches for “STP viewer free download” or “STEP file reader free download” are the same job: open the file here, orbit and measure. The CAD file stays on your device.

Are .STEP and .STP the same thing?+

Yes. Both are ISO 10303 STEP files. CAD systems pick one extension or the other; this viewer opens both. How to open a STEP file and how to open an STP file is the same action on this page.

Is this a STEP viewer, STP viewer, or 3D CAD file viewer?+

All three. STEP viewer and STP viewer are the same page (.STEP vs .STP). It is also a 3D CAD file viewer / CAD file viewer online / 3D STEP viewer / CAD STEP viewer for those formats: orbit, pan, zoom, and click two points. It does not open SolidWorks parts or STL today.

How do I view a STEP file without installing CAD?+

How to view a STEP file: open this page, Choose file, pick the .STEP / .STP from Files or Downloads. The model tessellates in the tab — a free program to open STEP files, not a desktop STEP file reader.