Core 3D ViewerHow to open STL files on iPhone
Open an STL model on your iPhone to inspect its shape before a discussion, review or handoff. Core 3D Viewer imports the file locally and lets you rotate it, zoom in and present it to someone else
Get the iPhone appFree download · iPhone, iOS 17+
Prepare the STL file
Save the .stl file in Files on your iPhone. When exporting from your design software, check its scale and keep a known physical dimension for comparison
Open the model
In Core 3D Viewer, open Library, tap +, and select your STL file. Rotate the model and zoom in to inspect its surfaces and overall shape
Check size before presenting it
Before relying on measurements or real-world AR placement, confirm that the imported model has the intended physical size. With Pro, add a dimension between known points and compare it with the original design
Share an interactive view
Open Share and create a link when you are ready. The recipient can inspect the model in a browser and see any dimensions or saved views you added
Before you start
STL shows geometry
The app displays STL geometry with a default material. Do not expect an STL file to reproduce the textures and surface finishes of your original design
Viewing and creating dimensions
Import and viewing are free. Adding dimensions or creating isolated saved views on your own model requires Pro. These tools are available to try on the included demo models
An example of the finished presentation
The table demo shows how a model with dimensions and saved views can be presented in the browser. It illustrates the viewer experience, not the appearance or materials of an imported STL file
Questions, answered
About STL on iPhone
Do I need an internet connection to open an STL file?
STL import and viewing happen on the device. Download a file from cloud storage first if you want to open it offline. Creating or opening a share link requires internet access
Can I prepare an STL for 3D printing in the app?
Core 3D Viewer lets you inspect and present the model. It does not provide a slicing workflow or generate printer instructions
Can I place an STL model in my room?
Yes. Tap AR in the iPhone app to place a copy of the model in your space. Check the source model's physical size first; the AR view lets you adjust its scale and does not show dimension annotations
Can someone view my STL without installing an app?
Yes. Create a share link in Core 3D Viewer. The app prepares a browser-compatible presentation of the model, and the recipient opens it without an app or account