What Is an STP File?

How to open and convert STP files

What to Know

  • An STP file is most likely a STEP 3D CAD file.
  • Open one with Fusion 360 or FreeCAD.
  • Convert to STL, DWG, DXF, etc., with those same programs or a dedicated converter.

This article describes the various formats that use the STP file extension, including how to open each type and how to convert one to a different format.

What Is an STP File?

A file with the .STP or .STEP file extension is most likely a STEP 3D CAD file saved in the Standard for the Exchange of Product Data (STEP) format. They contain information regarding 3D objects and are typically used to transfer 3D data between different CAD and CAM programs.

Other STP files could be RoboHelp Stop List files, which are plain text files that contains a list of words the associated Smart Index wizard should ignore when making a search index for help docs. For example, words like "or" and "a" are ignored from documentation searches to avoid showing non-relevant information.

Microsoft SharePoint uses STP files, too, but for template documents. Like any template, it serves as a way to quickly start making a web page using a similar design as another.

An STP file may instead be an XML-based Analysis Studio Project Information file that holds various settings and objects for Analysis Studio projects.

Screenshot of several STP files.

STP is also short for some non-file extension terms like software test plan, scheduled transfer protocol, secure transfer protocol, system test procedure, and shielded twisted pair.

How to Open an STP File

There are a number of software programs that can open STEP 3D CAD files, but Autodesk Fusion 360 is the most versatile since it runs on Windows, macOS, and mobile devices, as well as through a web browser.

Some other openers that work with this CAD file format include FreeCAD, ABViewer, TurboCAD, CATIA, and IDA-STEP. There are also free online STEP/STP viewers from eMachineShop and ShareCAD.org.

Adobe RoboHelp opens STP files that are for stop lists.

You can use Microsoft's SharePoint for opening STP files that are SharePoint Template files.

You can create new STP files in SharePoint through Site Settings > Administration > Go to Site Administration, and then Save site as a template in the Management and Statistics area.

Appricon's Analysis Studio program opens STP files that belong to that software, but we don't have any valid download links for it. CNET.com has a download for Analysis Studio, but there isn't a way to purchase the program. We've only included it here in case you happen to find a way to make it work.

How to Convert STP Files

The STEP 3D CAD software from above should also be able to convert the file to other formats, especially Autodesk Fusion 360. You can usually find the conversion tool in a Save as or Export menu/button.

You can also easily convert STP or STEP files to STL using Makexyz. It's an online converter, so it works with any operating system.

makexyz stp to stl converter

CrossManager is another converter, but it doesn't work online; you have to install it on your computer. However, it supports many more export formats in addition to STL, like PDF, OBJ, PRT, VDA, SAT, 3MF, and MODEL.

The trial version of CrossManager will only convert to 3D or 2D PDF. The other formats are available if the full program is purchased.

The trial version of ConvertCADFiles.com can convert STP to PDF but only if it's less than 50 KB. If it's not too big, you can try the free CoolUtils.com.

The FreeCAD program mentioned above should be able to convert STP to OBJ as well as DXF. There's plenty of information out there on converting STEP files to DWG, like this conversion guide on Stack Overflow.

If your STP file is in a different format that doesn't pertain to a 3D CAD file format, consider using the software that opens the file (linked in the previous section above) to convert it to a new file format. For example, SharePoint is most likely the best program for converting SharePoint Template files.

Still Can't Open It?

If you can't get your file to open with the programs mentioned above, or can't convert it with any of the tools mentioned, chances are that you're not actually dealing with an STP file in any of these formats.

The first thing you should do is double-check that the file extension truly reads STP or STEP (if you have a CAD-related file) and not something that's just spelled similarly, like STE. With suffixes that sound or are spelled like STP, don't immediately assume that the file formats can be used with the same applications.

In the STE example, the file opens with programs like Adobe Dreamweaver and Samsung Image Viewer, since it could be either a Dreamweaver Site Settings file or a Samsung IPOLIS Image file.

STR is another example that belongs to the dBASE Structure List Object file format and opens with dBase. It could instead be in other formats like PlayStation Video Stream, X-Plane Object String, BFME2 Strings, Kingsoft Strings, or Windows Screensaver File.

As you can see, you need to make sure that the file is actually related to the programs from above, otherwise, they can't be expected to open it. If your file isn't an STP or STEP file, research the actual file extension to learn what applications can open and convert it.

  • What is a .STP file used for?

    .STP files contain 3D image data used in CAD, so oftentimes .STP files are generated over the course of designing, manufacturing, and selling a product.

  • Can I open a .STP file in AutoCAD?

    Yes. From the Insert tab, select the Import panel, and then locate your .STP file. Click Open.

Was this page helpful?