CAD → 3D PDF converter · Online CAD viewer
STEP to 3D PDF Converter
Upload your STEP / STP file (or IGES, STL, OBJ, 3MF…), check the model in 3D and download it as an interactive 3D PDF that can be rotated and zoomed in PDF readers that support 3D content, such as Adobe Acrobat Reader on desktop — no CAD software needed.
Drop your STEP file here
or select a file from your computer
STEP · STP · IGES · IGS · BREP · STL · OBJ · 3MF · PLY · GLB · WRL · DXF 3D
Max size: 100 MB · 1 file at a time · Processed in your browser
Drag to rotate · Mouse wheel to zoom · Right-click and drag to pan · On touch screens: one finger rotates, two fingers zoom
View your CAD files
Drop your file here or select it from your computer. View only: the model is never modified.
STEP · STP · IGES · IGS · STL · OBJ · 3MF · PLY · WRL · GLB · DXF 3D · 3D PDF
Max size: 100 MB · Processed in your browser
Drag to rotate · Mouse wheel to zoom · Right-click and drag to pan · On touch screens: one finger rotates, two fingers zoom
How it works
Three steps, nothing to install and no account to create.
- STEP 1
Upload your file
Load your STEP or another supported CAD format. The format is detected automatically and you instantly see its data: units, dimensions, parts and bodies.
- STEP 2
View and convert
Check the model in the 3D viewer — rotate, pan, measure, hide parts — and convert it to 3D PDF with one click.
- STEP 3
Download
Download your 3D PDF and share it with people who need to review the model without CAD software. To view it in 3D they need a PDF reader that supports 3D content, such as Adobe Acrobat Reader on desktop.
Supported formats
STEP is the main format. Only formats the tool can actually read are listed as supported; native CAD formats must be exported to STEP first. What each format keeps when exporting, measured with one model, is in STEP, STL and 3D PDF compared.
| Format | Extensions | Support | Convert to 3D PDF | Notes |
|---|---|---|---|---|
| STEP | .step .stp .stpz | Supported | Yes | Tested with AP203 and AP214: parts, assemblies, solids, surfaces and colors. AP242 and .stpz are accepted but not yet tested with real files. |
| IGES | .iges .igs | Supported | Yes | Surfaces and solids. Tested with a simple sample file; assembly structure depends on the exporter. |
| BREP (OpenCascade) | .brep .brp | Supported | Yes | OpenCascade native format. Tested with a sample assembly. |
| STL | .stl | Supported | Yes | Triangle mesh (ASCII or binary, both tested). Has no units: mm are assumed. |
| OBJ | .obj | Supported | Yes | Mesh with groups, tested with a sample file. External .mtl materials are not loaded. |
| 3MF | .3mf | Supported | Yes | Mesh. Tested with a single-object file; multiple objects, multiple materials or format extensions have not been tested yet. |
| PLY | .ply | Supported | Yes | ASCII or binary mesh, with per-vertex color. Tested with a colored ASCII PLY. |
| glTF / GLB | .glb .gltf | Supported | Yes | Tested with GLB. A self-contained .gltf is accepted but not tested; external .bin files or textures are not loaded. |
| VRML | .wrl .vrml | Experimental | Yes | VRML 2.0 / VRML97 only (tested with a simple file). VRML 1.0 is not supported. |
| DXF 3D | .dxf | Experimental | Yes | 3D face geometry only (3DFACE, POLYFACE, MESH); tested with 3DFACE. 2D drawings and ACIS solids are not converted. |
| PDF 3D | Experimental | Viewer only | Reads the tessellated PRC model in the PDF (like the ones made here). U3D and B-Rep/compressed PRC: detected and extractable, but not drawn yet. | |
| SolidWorks | .sldprt .sldasm | Requires intermediate conversion | After exporting to STEP | Export it as STEP from SolidWorks (File › Save As › STEP AP214/AP242). |
| Parasolid | .x_t .x_b .xmt_txt .xmt_bin | Requires intermediate conversion | After exporting to STEP | Requires the Parasolid kernel (commercial license). Export to STEP from your CAD software. |
| CATIA V5 | .catpart .catproduct | Requires intermediate conversion | After exporting to STEP | Requires a commercial converter. Export to STEP from CATIA. |
| Autodesk Inventor | .ipt .iam | Requires intermediate conversion | After exporting to STEP | Export to STEP from Inventor (Export › CAD Format › STEP). |
| PTC Creo | .prt .asm | Requires intermediate conversion | After exporting to STEP | Export to STEP from Creo (Save a Copy › STEP). |
| Siemens NX | .prt | Requires intermediate conversion | After exporting to STEP | Export to STEP from NX (File › Export › STEP). |
| Solid Edge | .par .psm .asm | Requires intermediate conversion | After exporting to STEP | Export to STEP from Solid Edge (Save As › STEP). |
| Fusion 360 / Rhino / SketchUp | .f3d .3dm .skp | Requires intermediate conversion | After exporting to STEP | Export to STEP, OBJ or STL from the source application. |
“Supported” means the format has been tested with sample files, not with every variant. Complex files, files with external references, multiple materials or close to the 100 MB limit may have limitations; if a file cannot be read, the tool says so with a message.
What is a 3D PDF used for?
A 3D PDF puts the model inside a PDF document, a format most people already know how to handle. In 3D-capable readers the model can be rotated and explored; other readers only show a static image. It is a practical way to show a design without handing over the original CAD file.
- Sharing CAD designs with customers
- Design reviews
- Technical presentations
- Engineering documentation
- Supplier reviews
- Sharing models with people who don’t have CAD
- Product documentation
- Sales presentations
- Internal engineering reviews
- Sending models to customers without sharing the original CAD file
A real 3D PDF, not a screenshot
The PDF you download contains a 3D annotation (ISO 32000) with the model in PRC format (Product Representation Compact, ISO 14739-1), the same format used by technical 3D PDFs. It includes the tessellated geometry of every body, the assembly part structure with its names and the colors of each part or face. When you open it in Adobe Acrobat you can rotate, zoom, switch between views (isometric, front, top…) and show or hide parts in the model tree.
The STEP file is read by OpenCascade — an open-source CAD kernel — compiled to WebAssembly, which turns the exact B-Rep geometry (solids and surfaces) into triangles at the quality you choose. Then the PRC is written and the PDF is generated, all in your browser.
Why PRC and not U3D?
Both formats are valid inside a 3D PDF. PRC is preferred for CAD: it keeps the assembly structure, names and per-part colors, and can carry exact geometry; U3D is an older mesh format designed for visualization. This tool writes PRC with tessellation (triangle meshes). Exact B-Rep geometry inside the PRC would require a third-party commercial SDK; the architecture is ready to add it as an extra converter.
3D PDF compatibility
To view the interactive 3D model you need a PDF reader that supports 3D content, such as Adobe Acrobat or Acrobat Reader. In Acrobat, 3D content may be disabled at first for security: a yellow bar appears and you just choose Options › Trust this document, or turn on Preferences › Multimedia & 3D › Enable Playing of Multimedia and 3D content. Readers without 3D support (browsers, most mobile apps) show the cover page and a preview image of the model.
Privacy and limits
Your files never leave your browser
CAD files are often confidential, so here they are never uploaded to a server: reading, 3D viewing and conversion run on your own device (WebAssembly and Web Workers). Nothing is stored: the file only exists in the tab’s memory and is cleared when you click Remove, load another file, or close or reload the page.
- The actual file content is checked, not just the extension.
- The file is processed in an isolated thread (Web Worker) with a time limit.
- File content is never executed; only its geometry is read.
- File names are sanitized before being used for downloads.
Usage limits
Large files depend on your device’s memory. If a very heavy model is slow, use the “Low” tessellation quality.
Frequently asked questions
What is a 3D PDF?
It is a PDF file that, besides regular pages, contains a 3D model embedded in PRC or U3D format. In a compatible reader the model appears on the page and can be rotated, zoomed and explored part by part.
Can I convert a STEP file to 3D PDF?
Yes, that is the main purpose of this tool. Drag your .step or .stp file into the converter, check the model and click Convert to 3D PDF. It has been tested with AP203 and AP214, both parts and assemblies; AP242 is accepted but not yet tested with real exports.
Can I open the PDF in Adobe Acrobat?
Yes. Adobe Acrobat and Acrobat Reader display the 3D model. If you see a yellow bar saying 3D content is disabled, choose Options › Trust this document or enable it in Preferences › Multimedia & 3D. The full guide is in how to enable 3D in Adobe Acrobat Reader.
Do I need CAD software installed?
No — neither to convert nor to view the result. Whoever receives the 3D PDF only needs a 3D-capable PDF reader such as Acrobat Reader.
Which CAD formats can I upload?
STEP/STP, IGES/IGS and BREP (tested with sample files); STL, OBJ, 3MF, PLY and glTF/GLB as meshes; VRML 2.0 and DXF with 3D faces as experimental. Native formats (SolidWorks, CATIA, Inventor, Creo, NX, Solid Edge, Parasolid) must be exported to STEP first.
Can I view a STEP file without installing CAD software?
Yes. The 3D Viewer tab opens STEP files right in your browser, with rotate, zoom, standard views, part tree and distance measurement.
Can I open a STEP file in my browser?
Yes, in any modern browser with WebGL (Chrome, Edge, Firefox, Safari), on mobile too. The CAD engine is downloaded once (about 8 MB) and then reused.
Does the PDF really contain the 3D model?
Yes. It carries a 3D annotation with the model in PRC format: geometry, part structure and colors. It is not an image. The preview you see in readers without 3D is just the annotation’s fallback appearance.
Can I rotate the model inside the PDF?
Yes. In Acrobat, click the model to activate it and drag to rotate. The 3D toolbar also lets you pan, switch views and use the model tree.
Can I zoom?
Yes, with the mouse wheel or a pinch gesture, both in the web viewer and inside the PDF in Acrobat.
Are the model’s colors kept?
Yes, when the file includes them: per-part and per-face colors in STEP (common in AP214 and AP242), and, in meshes, colors stored in the file itself (tested with per-vertex color in PLY; external OBJ .mtl materials are not loaded). Parts without color are shown in gray.
Can I convert assemblies?
Yes. The assembly structure is preserved: in the PDF every part appears with its name in Acrobat’s model tree, and a page with the list of components is included.
Are my files stored?
No. Everything is processed in your browser and nothing is uploaded to a server. The file is cleared from memory when you remove it, load another one or close the page.
Can I use the viewer on my phone?
Yes. Rotate with one finger, zoom with a two-finger pinch and pan with two fingers. On phones with little memory, moderately sized files work best.
Can I edit models?
No. It is strictly a viewer and converter: you cannot move vertices, change dimensions, do boolean operations or edit sketches. You can only hide parts and measure distances to review the model.
Can I convert STL to 3D PDF?
Yes. STL, OBJ, 3MF, PLY and GLB are converted too. Keep in mind they are meshes: they have no exact geometry or units (millimeters are assumed).
What is the difference between a regular PDF and a 3D PDF?
A regular PDF only contains flat pages (text, drawings, images). A 3D PDF also includes an interactive three-dimensional model inside the page that can be rotated, zoomed and explored like in a CAD viewer.