Do you have a STL 3D model file that will not open correctly? If so, our free-to-use STL 3D model repair tool may be able to help. Our tool analyses the content of your STL file and is able to determine if the file structure and content (i.e., vertices, faces, and materials) are valid. Our tool will let you know what is wrong with your STL 3D model file and attempt to fix it.
Or drag and drop your files here to upload.
A maximum of 20 files can be uploaded at once.
Here are 3 simple steps to repair your STL using our fast and free repair tool.
Our STL repair tool will not intentionally reduce the number of vertices or faces in your 3D model.
Yes! Our STL repair tool is 100% free to use.
No, you can repair as many files as you wish. We do not have any limits when using our STL repair tool.
We aim to process STL repairs as quickly as possible; this usually takes around 5 seconds; however, this may be longer depending on the file size and data needed to be repaired.
Once your STL has been selected, it will undergo some initial checks to verify that the file has some basic information. If the initial checks pass, we then upload the file to our servers for more detailed analysis.
Yes, of course it is! Your STL, once repaired, is deleted 15 minutes after upload, and any download link will expire after this time.
Yes! Our STL repair tool will run on any system with a modern web browser.
| 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 modelling 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 flavours: 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.
As is common amongst 3D model file formats, STL file formats may contain data within their header to help identify the type of file should the filename extension prove to be inaccurate or missing. With the header data from the STL 3D model file, we are able to determine core information such as object count, vertex count, faces, textures, and other information, which can then be used to check the validity of the file.
This data forms the core element of any STL model and, if damaged, cannot be easily recovered. Our STL repair tool will try its best to repair and reconstruct any 3D model file it detects to be missing geometric data.
