Free STL Viewers for Dental Scans and Models

This guide is for dentists, dental technicians, students and clinic IT staff who receive STL files (an intraoral scan, a printed model, a crown or a surgical guide design) and simply need to open them, check them or measure them, without buying CAD software.

The short answer: for dental files, install nothing first and open the file in exocad webview, which is free, needs no account and runs in a browser, on Windows, iPhone, iPad and Android. On a Mac, Preview already opens STL. If you need to measure, use the free PrusaSlicer measurement tool. Do not count on Windows 3D Viewer any more: Microsoft has deprecated it and removed it from the Microsoft Store.

Which free STL viewer for which job

Opening STL files on Windows 10 and Windows 11

For years the answer to “what opens STL files on Windows” was Microsoft’s 3D Viewer. That has changed. Microsoft’s documentation for IT professionals states that 3D Viewer was deprecated in February 2026 and removed from the Microsoft Store on 1 July 2026. Existing installations keep working, but you cannot install it again, and it was never preinstalled on Windows 11. A fresh Windows 11 workstation therefore has no STL viewer out of the box.

The simplest replacement for dental work is exocad webview. On Windows 10 and 11 it is in the Microsoft Store as “exocad view”; on a locked-down clinic PC where staff cannot install apps, the same viewer runs in the browser at webview.dental. It opens .stl, .obj, .ply and several other mesh formats, and ZIP archives that contain them. It loads several files at once, so you can open the upper jaw, the lower jaw and a crown together, and it lets you make each mesh transparent to see contacts and margins.

If the computer is also used to prepare 3D prints, the printer’s own software works as a viewer too. Formlabs PreForm imports STL, OBJ and 3MF, and you can install it without owning a Formlabs printer. PrusaSlicer and UltiMaker Cura open STL on Windows, macOS and Linux. Resin-printer slicers such as CHITUBOX also open STL and OBJ, but most of them are shareware with paid tiers.

Opening STL files on a Mac

macOS needs no extra software for a quick look. Apple’s Preview User Guide lists STL, PLY and OBJ among the 3D formats Preview opens. Select the file in Finder and press the Space bar for Quick Look, or open it in Preview to orbit, pan and zoom. Apple does not list measuring tools for 3D files in Preview, so use it to look, not to measure.

For coloured intraoral scans or several meshes in one scene, use exocad webview in Safari, Chrome or Firefox. There is no separate macOS app, but the web version does the same job. PrusaSlicer, PreForm and Cura all have Mac versions if you need measuring or print preparation.

Viewing STL files on iPhone, iPad and Android

exocad webview has free apps for iPhone and iPad (iOS 15.6 or later) and for Android, with no registration and no in-app purchases. The apps load files from iCloud, Dropbox, Google Drive and similar services, which suits a dentist checking a lab design between patients or showing a planned restoration to a patient on a tablet.

If your lab works with 3Shape, the free 3Shape Communicate app shows scans and designs that were sent through Communicate, together with the order form and comments, and lets you approve or reject a design. It is a case portal, not a general file viewer, and 3Shape says TRIOS users on Unite 24.1 and newer use Unite Cloud instead.

Using an STL viewer online

An online viewer is handy when you cannot install anything, but remember what an intraoral scan is: patient data. Prefer a viewer from a dental software maker you already trust over a random “STL viewer online free” site, and check your practice’s privacy rules before uploading files anywhere. exocad webview’s browser version at webview.dental is the one we recommend for dental files. SelfCAD also runs in the browser and adds mesh editing and measurements; its free plan is limited, so it counts as shareware (conditionally free).

Measuring an STL model for free

“STL viewer and measure” is a common search, and the most popular dental viewer does not answer it: exocad does not list measuring tools for webview, so do not rely on it for measurements. For that, use PrusaSlicer. Since version 2.6 it has a measurement tool in the left toolbar that detects points, edges, circles and planes. Prusa’s help centre describes measuring distances between vertices, edges and planes, angles between non-parallel edges or planes, and the distance between the centres of two holes. Prusa also notes the limits: you can measure within one object but not between separate objects, and it does not measure surface area.

MeshLab, a free open-source (GPL 3.0) mesh tool from the Visual Computing Lab of ISTI-CNR, also has measuring tools and is better for inspecting and repairing damaged meshes. Its current release is 2025.07, for Windows, macOS and Linux.

STL, PLY or OBJ: which file to ask for

• STL stores surface geometry only. It is what printers, slicers and most CAD systems expect, so ask for STL when the file is going to be printed or milled.
• PLY can carry colour. exocad advises exporting PLY from the scanner software when you want a coloured intraoral scan to keep its appearance, for example for case discussion or patient education.
• OBJ can carry textures and is widely supported by viewers, slicers and Preview on the Mac.

If a scanner platform such as Medit Link or 3Shape Unite can export both, keep the PLY for viewing and send the STL to the printer or lab.

Limitations

• None of these viewers is dental CAD. They do not design crowns, bridges or dentures; for that see our guide to free dental CAD viewers and the article on exocad DentalCAD licences.
• exocad does not describe webview as a diagnostic tool, and slicer measurements are for print preparation. Do not base clinical decisions on them.
• STL is not CBCT. A cone-beam scan arrives as DICOM and needs a DICOM viewer; see free dental DICOM viewers.
• Implant plans from the Simplant Planning Service are not opened as STL: use the free Simplant Viewer and Simplant Editor.
• Windows 3D Viewer still works where it is installed, but it is deprecated and cannot be reinstalled, so do not build a clinic workflow around it.

FAQ

What opens STL files for free?

exocad webview (browser, Windows, iOS, Android), Preview on a Mac, and free slicers such as PrusaSlicer, UltiMaker Cura and Formlabs PreForm. For dental scans and lab designs, exocad webview is the most convenient because it keeps scan colours and opens several jaws and restorations together.

Does Windows 11 have a built-in STL viewer?

No. 3D Viewer was not preinstalled on Windows 11, Microsoft deprecated it in February 2026 and removed it from the Microsoft Store on 1 July 2026. Install “exocad view” from the Microsoft Store or use the browser version instead.

Is there a free STL viewer for iPhone and Android?

Yes. exocad webview is free on the App Store and Google Play and opens files from iCloud, Dropbox or Google Drive. 3Shape Communicate’s app shows cases shared through Communicate.

How do I measure an STL file for free?

Open it in PrusaSlicer and use the measurement tool in the left toolbar to measure distances, angles and hole diameters. MeshLab is an alternative if you also need to repair the mesh.

Can I view a 3Shape Communicate case as STL?

You can view it in the Communicate portal or app. Whether you can download the raw STL depends on how the sender shared the case. Once you have the file, any viewer above opens it.

STL vs OBJ: which is better for dental scans?

Use STL for printing and milling, because every slicer and CAD system reads it. Use PLY or OBJ when you want to keep colour or textures for viewing and case discussion.

Last updated: 7 October 2026 · Dents-Soft editorial team. Licence, version and platform details are checked against each developer's official documentation; none of the tools listed here should be treated as a certified medical device unless its vendor says so.