What CAD file formats does CADDaddy support?

CADDaddy supports STEP, IGES, STL, 3MF, OBJ, FBX, GLTF/GLB, PLY, DAE, 3DS, and VRML for online viewing. We're continuously adding support for more formats.

Is CADDaddy really free to use?

Yes, CADDaddy offers a free tier with 5 file views per month. Professional plans are available for higher usage with additional features and priority support.

Do I need to install any software to use CADDaddy?

No installation required. CADDaddy works entirely in your web browser on any device - Windows, Mac, Linux, or mobile.

How fast does CADDaddy load CAD files?

Most CAD files load in under 5 seconds. Our optimized viewer provides 60fps performance for smooth 3D navigation.

Can I edit CAD files with CADDaddy?

CADDaddy offers light editing capabilities including transform, scale, and rotate operations. For full CAD editing, we recommend dedicated CAD software.

How do I convert STEP to STL files?

Converting STEP to STL is easy with CADDaddy. Simply upload your STEP file, view it in our online converter, and export as STL. Our free STEP to STL converter works entirely in your browser with no software installation required.

Is my CAD data secure with CADDaddy?

Yes, your files are processed securely. Files are processed in your browser when possible, and server processing uses encrypted connections with automatic deletion.

.stlbrowser only

Free Online STL File Viewer

Qualitys can open STL files online — without installing CAD software.

Open STL file See pricing

What is a STL file?

STL is a standard CAD exchange format used by quality teams to review parts and assemblies. CADDaddy opens .stl files locally in your browser using WebAssembly — your file stays on your device until you choose to save or share.

What you can do with STL files in CADDaddy

CADDaddy helps quality teams open STL files online. Drop a file, inspect geometry, measure dimensions, and export to STL or GLB — free to start.

Instant browser viewing

Open files in seconds. No install, no account required to start inspecting.

Trusted units & bbox

STEP/IGES load in millimetres with a unit chip and one-click L×W×H envelope.

Measure & section

Point-to-point distance, bounding box, and cross-section slices for review.

Export to STL or GLB

One-click mesh export for 3D printing, web, or downstream tools.

Works on phone & desktop

Review supplier files from a phone browser or factory PC — no CAD license.

Lifetime Pro unlock

$19 one-time for unlimited files, measure, section, and clean exports.

STL Viewer FAQ

How do I open a STL file online?+

CADDaddy helps quality teams open STL files online. Drop a file, inspect geometry, measure dimensions, and export to STL or GLB — free to start.

Do I need SolidWorks or AutoCAD to view STL?+

No. CADDaddy opens .stl files in Chrome, Safari, or Edge with no desktop CAD license.

Can quality teams measure STL files online?+

Yes. Free users get a measure trial; Pro unlocks distance, bounding box, face area, and section views for supplier review.

Is CADDaddy free?+

Viewing is free with no account. Guest export is limited daily; Professional is a one-time $19 lifetime unlock for unlimited files and tools.

Other formats CADDaddy supports

STEP Viewer IGES Viewer OBJ Viewer

View your STL file now

No install, no account required. Drop your file and start inspecting.

Open viewer