Free Online U3D to STL Converter

You can use our U3D to STL conversion tool to quickly and easily convert your 3D model files for free. You may upload up to 20 files at one time, and our batch U3D to STL converter will process each 3D model and present you with a download link for each file once completed.

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Select File(s)

Or drag and drop your files here to upload.
A maximum of 20 files can be uploaded at once.

Please note: Your U3D file, once uploaded to our server, will be deleted 15 minutes after upload, so please download your converted U3D file before this time.

Our 3D model U3D to STL tool will load your U3D file and, where supported, attempt to extract all the relevant 3D features, such as geometry, textures, and animations. To access the 3D conversion configuration options, click the button when you have selected your files. The current options support the ability to voxelize your 3D model and more.

How to Convert your U3D to STL Online?

Here are two simple steps to convert your U3D to STL using our fast and free U3D converter tool.

Upload your U3D file

Click the "Upload a U3D File" button, then select a U3D to upload. The maximum file size is 100MB.

Download your STL

Click the download link to receive your STL file.

Frequently Asked Questions

How can I convert my U3D file to STL?

First, click the "Upload..." button and select your U3D file to upload. Your U3D file will be uploaded to our servers. When the U3D to STL conversion has completed, you can download your STL file right away.

How long does it take to convert my U3D to STL?

We aim to process all U3D to STL conversions as quickly as possible; this usually takes around 5 seconds; however, this can be longer for certain files, so please be patient.

How accurate is the U3D to STL conversion?

We aim to provide the best conversion experience. Our tools are under constant review and development, with new features being added every week.

How does converting U3D to STL work?

In order to successfully convert an U3D formatted file to the STL format, our converter tools will perform several initial checks to ensure the file provided is indeed an U3D file. There are many files out there where the file type extension does not match the data contained within the file. Along with these file type checks, our tools will do additional checks to ensure the file is correctly formatted to match the provided file type. There are many tools out there that do not always create U3D files to the exact specification.

Take your U3D file

An U3D file is a binary data file containing 3D data that makes up the 3D model, including vertices, faces, texture coordinates, and more. To guarantee efficient conversions, our tool will check all data that is contained within the U3D file and remove any information that is duplicated. This not only ensures the conversion completes more quickly, but also the generated STL file size is smaller.

Convert the data from U3D to STL

Now that the data from the U3D file has been processed, our tool can apply any conversion specified options, such as enabling Voxel mode, and with these applied, prepare the data to be converted to the final STL file format. Part of this process ensures checking the capabilities of the STL format and removing any data that cannot be represented.

Save to the STL format

At this point, the U3D to STL conversion tool will have the 3D model in a state that is ready to be transferred to the STL format. Our tool creates the STL file, ensuring all the model data is present and is formatted to match the STL file specification to ensure the file opens in compatible STL file editors. To ensure a compact file size, our U3D to STL converter will always save the STL file in a binary format.

File format information for U3D and STL

Extension	U3D
Full Name	Universal 3D
Type	3D Model
Mime Type	model/u3d
Format	Binary

U3D files are a 3D model format designed specifically for use in conjunction with PDF documents. The U3D format stores 3D model data in a manner that allows the file to then be embedded within a PDF document, enabling rich 3D content within a standard PDF.

Within a U3D file are the various data elements that make up the 3D model, including vertices, faces, normals, and texture coordinates. Along with this basic geometry, the face materials are also stored, which describe how the 3D object's surface should be rendered.

Support for exporting 3D content to the U3D format can be found in some 3D modeling software; in particular, the popular modeling software Daz Studio contains a U3D exporter.

U3D Converter Capabilities

Our U3D 3D Model/Mesh tool does not support any color material data contained within U3D files, so the converted file will not contain any color information.

Extension	STL
Full Name	Standard Triangle Language
Type	3D Model
Mime Type	application/vnd.ms-pki.stl
Format	Text
Opens With	Blender, MeshLab, CAD Assistant, DAZ Studio

The STL, or Standard Triangle Language, file format has been around since the '80s and is supported by most modern 3D modeling applications. In particular, the STL format has become something of a standard format within the area of 3D printing, despite the rise of more modern formats such as 3MF.

STL files come in two flavors: binary or text format. The text format is human-readable, making it easy to perform manual edits, but can lead to very large file sizes. As you can imagine, the binary format is much more compact and represents the majority of the STL files you are likely to encounter.

The format itself is very simple; the 3D model is represented by a sequential list of triangles, with each triangle defined with 3 points consisting of their X, Y, and Z positions, along with an additional vector that contains the face normal (the direction the face is pointing). There is an additional attribute block for each triangle; however, this is largely unused and thus unsupported.

STL Converter Capabilities

Our 3D conversion tool does not support color or material information in STL files, so your file will not contain any color information.

Information for converting from U3D to STL

Your U3D file will be converted to a STL file using our unified 3D model and mesh conversion tool. Our U3D 3D tool performs accurate conversions of 3D elements such as vertices, faces, normals, and relevant material information. Our tool will not attempt to transfer any color information if it is present in your U3D file; your final 3D model will contain only geometry data.