ViewSTL is a browser-based app that can open 3D files such as OBJ and STL without having you sign in or sign up for an account. It’s a reliable option for users looking to open 3D files without downloading and installing an app. Since it’s browser-based, an active internet connection is required.

Viewing any document is as simple as dragging and dropping a file. Alternatively, you can browse your device (denoted by a file logo), which directs you to the file directory of your device, and there’s also an option to open a file through a URL.

Once the file’s uploaded, you can use the top menu bar to toggle between multiple orientations, turn on the grid, take screenshots, export, or even change the background color. Using this program is as easy and intuitive as it gets.

• Platform: Browser-based
• Cost: Free
• Rating: N/A

A fairly straightforward app, Exocad has an intuitive user interface (UI) across all the different platforms, from the web app to the iOS, Android, and Windows versions, and can be a great pick for beginners. It can open popular 3D file formats such as PLY, STL, and OBJ. It’s completely free to use and doesn’t even require sign-in or registration.

Exocad also allows users to import 3D files via cloud services like iCloud and Google Drive. To open a 3D file, you need to install the app on your device or visit the web app. Then click on “Load file” or “Google Drive” and select the desired file from your device. If you wish to use iCloud Drive, choose the “iCloud Drive” location after clicking on “Load File”.

The app also prompts if you wish to import textures for the mesh; if you want to do this, go ahead and import the texture right away, as it’s not possible to add them later on. Once you’ve imported the 3D file, you can toggle the shading as well as change the field of view by up to 90°. Standard features such as zooming and panning work as usual; use your fingers, mouse, or trackpad to interact with the object.

• Platform: Browser-based, Windows, Android, iOS
• Cost: Free
• Rating: 4.6 (Google Play), 4.5 (App Store)

Emb3D doubles as a 3D model viewer and dedicated Android and iOS app for a better mobile experience, and no matter what version you’re going for, they all offer an intuitive UI. Using the online viewer is easy, and all you need to do is click on the “Load Model” option at the bottom of the viewer, then choose the file and click “Load”. It supports 3DS, GLB, OBJ, STL, ZIP, and other popular file formats.

If you’re using the mobile app, click on the ‘+’ icon at the bottom of the screen and select the file you wish to import. Once imported, click on the file from the menu, and you’re all set to view that 3D file. The tools on the web app and the iOS and Android apps are similar. As for functionality, in addition to viewing, there’s an option to select the mesh, change the background, and even toggle the lights.

The web app has an option to export the file, whereas using the iOS or Android app will let you share the model, view the model offline, and even try the experimental AR More.

• Platform: Browser-based, iOS (iPad and iPhone), Android
• Cost: Free (in-app purchases available), $5/month or $47/year for Pro subscription
• Rating: 3.7 (Google Play), 4.3 (App Store)

This popular STL viewer app has high ratings and is free to download, with inexpensive in-app purchases available. Users are enthusiastic about its capabilities for seeing minute details and keeping STL files remotely organized when working away from their computers. Other well-liked features are the capabilities to examine meshes, delete parts of models, and edges detection.

It’s a very intuitive and easy-to-use app, and users praise its speed and simple interface, although a downside is that, as mentioned by a reviewer, you can’t share the files. If you opt for the in-app purchases, you can find the volume of a specified part of the STL file, view the model in its actual color instead of the default options, and remove ads. The app creators are responsive to user queries and issues. Another nice aspect of this viewer is it appeals to users of all levels; it offers more advanced features while being straightforward enough for newbies to 3D printing.

• Platform: Android
• Cost: Free with in-app purchases
• Rating: 4.3 (Google Play)

3D Model Viewer – AR View is a 3D model viewer for iOS devices (iPhone and iPad) that can easily open files such as 3DS, OBJ, DAE, Blend, and STL, and you can even import files from iCloud. Although the app is free to use, it’s ad-supported and you can’t import models over 30 MB or add custom backgrounds in the basic version.

The app’s interface is clean and makes it an app that’s easy to understand and use. The bottom menu bar houses valuable tools that let you toggle the background, AR mode, material type, shadow, and camera, among others. You can use standard features such as a rotation along the center, panning with two fingers, and zooming with two fingers to interact with the 3D model.

• Platform: iOS (iPhone and iPad)
• Cost: Free with in-app purchases
• Rating: 4.2 (App Store)

Online 3D Viewer is a cloud-based 3D viewer that you can access from any device with a supported browser. Opening a file is as simple as clicking the file logo, which is located at the top-left corner, just below the viewer logo. Users also have an option to open a file through a URL or by using drag-and-drop.

The most helpful feature is the measurement tool, which allows you to measure the distance between two clicked points as well as the angle between them. There’s also an option in the left menu to view a specific mesh of the model selectively, and users can even check the details about the selected materials; the right menu contains options to change the background or switch to dark mode.

With the help of the export option, you can choose to export the files in PNG format or any other format from the drop-down menu. Furthermore, there’s an option to generate a shareable link, and it doesn’t require users to sign up.

• Platform: Browser-based
• Cost: Free
• Rating: N/A

3D Model Viewer is an open-source 3D viewer app for Android that’s both lightweight and fast, but has an unpolished UI. It also has some demo 3D models in case you want to check out what your 3D model would look like inside this app.

Viewing a 3D model inside this app is straightforward; you need to click on “Load model”, which will redirect you to the smartphone’s file directory. Now, click on the file and its format (OBJ, STL, DAE), and you’re all set to view the model.

3D Model Viewer has many interactive features, such as toggling the light, background, texture, animation, and wireframe. Moreover, the developer hints that additional features such as glTF support, 3D without glasses, and AR view are on the way (although, at time of writing, the app was last updated in July 2022).

• Platform: Android
• Cost: Free
• Rating: 3 (Google Play)

Creators3D Online Viewer is a browser-based 3D viewer that can open various 3D files. Users don’t need to sign up to access this program, and uploading a file is as easy as dragging and dropping or clicking on “Drop Files Here”.

This online application has a variety of tools, from Scene, Lightning, and Display effects to Sharing and Export options, all catering to enhance the user experience. This viewer is similar to ViewSTL, but it supports more 3D file types and has interactive tools integrated into the viewer.

There’s also an option to upload a file to the cloud and share that as a link, but the user needs to sign up for an account; on the other hand, converting the same document to glTF (GLB) or USDZ and downloading only requires one click.

• Platform: Browser-based
• Cost: Free
• Rating: N/A

CAD Assistant is an offline 3D CAD viewer available for all major platforms, including iOS and Android. It incorporates the use of open-source libraries and supports a wide range of CAD file formats, including STEP, glTF, PLY, STL, OBJ, and 3DM.

You can look at additional mesh data and toggle between various mesh modes such as Hollow Mesh, Wireframe, and Mesh Edges. Opening a file is as easy as clicking on the File icon and selecting the desired file.

The interface is well-optimized for finger gestures, which you can use to zoom in and out as well as rotate the 3D model. However, to “Pan”, you need to click on the 3D option in the left menu bar and click on the “Pan by single touch” option. Overall, it may take beginners a bit of navigating to fully get their bearings with this option.

• Platform: Windows, Linux, MacOS, Android, iOS
• Cost: Free
• Rating: 4.5 (Google Play)

AVE3D Viewer is not only a great option for STL file viewing, but the basic free version supports a large number of other file types as well, like OBJ, PLY, GLTF, and plenty more, so it’s an “all-in-one” app in that regard. Additionally, you can opt for a paid version to support some other file types like FBX, AMF, and 3DS.

Some of this app’s standout features include screenshot shooting capability, point cloud display, and even a rather unique element that allows you to display a model on your phone as if it’s an X-ray.

Users praise its sleek and easy-to-use interface, smooth controls, large file format selection (even with the free version), and clear layouts.

• Platform: Android
• Cost: Free with in-app purchases
• Rating: 4.3 (Google Play)