Repair your STEP Online

Do you have a STEP 3D model file that will not open correctly? If so, our free-to-use STEP 3D model repair tool may be able to help. Our tool analyses the content of your STEP 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 STEP 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.

Please note: Your STEP, once uploaded to our server, will be deleted 15 minutes after upload.
If our tool offers the option to repair your file, please ensure you download the repaired file within this time period.

How to Repair your STEP Online?

Here are 3 simple steps to repair your STEP using our fast and free repair tool.

Upload your STEP

Click the "Select File" button, then select a STEP file. The maximum file size is 100MB.

Analysis and Repair

Your STEP file will be analysed, and our tool will attempt to repair your STEP file if possible.

Repair or Convert your STEP

Select an option to either repair or convert to receive your repaired STEP file.

STEP file format information

Full NameSTEP-File
Type3D Model
Mime Typeapplication/octet-stream
Opens WithCAD Assistant

STEP files are a 3D file format used to store complex 3D object definitions in a standard format to facilitate data transfer between compatible 3D modelling and CAD (Computer Aided Design) applications. In addition to storing 3D object data, the STEP format can store additional information such as materials, tolerances, and other relevant data.

The STEP format was first released in the early 1990's, has become a standard for 3D object storage, and is used in automotive, electronics, and other industries. STEP files can be opened in most modern CAD applications and can be imported into many 3D modelling applications too.

The file content is ASCII text-based and conforms to the ISO-10303-21 standard. The 3D object contained within the STEP file is described using a combination of points, lines, and edges. Due to the format being ASCII text, complex objects can lead to large file sizes. In addition to large file sizes, some complex STEP files can take a long time to open within editing applications, even on a high-spec, modern computer.

Repairing a STEP File

STEP 3D Model File Header Data

As is common amongst 3D model file formats, STEP 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 STEP 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.

Vertices, Faces and Geometry

This data forms the core element of any STEP model and, if damaged, cannot be easily recovered. Our STEP repair tool will try its best to repair and reconstruct any 3D model file it detects to be missing geometric data.

Frequently Asked Questions

Will the quality (vertices or faces) be affected?

Our STEP repair tool will not intentionally reduce the number of vertices or faces in your 3D model.

Is it free to use the STEP file repair tool?

Yes! Our STEP repair tool is 100% free to use.

Are there any usage limits when repairing my STEP file?

No, you can repair as many files as you wish. We do not have any limits when using our STEP repair tool.

How long does it take to repair my STEP?

We aim to process STEP 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.

What does the STEP repair process involve?

Once your STEP 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.

Is it safe to repair my STEP on

Yes, of course it is! Your STEP, once repaired, is deleted 15 minutes after upload, and any download link will expire after this time.

Can I repair my STEP on Windows, Linux, Android, iOS or Mac OS?

Yes! Our STEP repair tool will run on any system with a modern web browser.