What is a .stp file?
A .stp file is a STEP 3D model. Its registered MIME type is model/step, which places it in the 3D model family of formats.
STP is a binary format: the contents are not readable text, so opening it in a text editor shows scrambled characters.
Files of this type usually begin with the bytes 49 53 4F 2D 31 30 33 30 33 2D 32 31 3B. That signature is how programs recognise the format even when the extension is wrong or missing.
The same format is also saved with the extensions .210, .p21, .step, .stpnc.
STP file format details
| Extension | .stp |
|---|---|
| Format | STEP 3D model |
| MIME type | model/step |
| Category | 3D model |
| Text or binary | Binary |
| File signature | 49 53 4F 2D 31 30 33 30 33 2D 32 31 3B |
| Registered with IANA | Yes |
| Other extensions | .210, .p21, .step, .stpnc |
How to open STP files
| Windows | STP files (STEP 3D model) are made by specific software. The reliable way to open one is with the program that created it; a generic viewer will only show raw data. |
|---|---|
| Mac | The same applies on a Mac: look for a Mac version of the program that makes STP files. |
| iPhone and iPad | Phones rarely open this type of file directly. The viewer above can show what is inside it without installing anything. |
| Android | The same applies on Android. The viewer above shows the first bytes of the file so you can confirm what it is. |
Can you convert a .stp file?
TapToConvert does not convert STP files. The usual route is to open the file in the program that made it and use its Export or Save as option.
STP file FAQ
What is a .stp file?
A .stp file is a STEP 3D model, with the MIME type model/step.
How do I open a .stp file?
With the program that created it. The viewer on this page shows what is inside without installing anything.
Is a .stp file safe to open?
STP files hold data rather than programs, but any file from an unknown source can be crafted to exploit the software that opens it. Keep that software up to date. The viewer on this page only reads the bytes and never runs anything.
What is the MIME type of .stp?
model/step. Web servers send this type so browsers know how to handle the file.
Is STP a text or binary format?
Binary. Its contents are not readable as text.
File type facts come from the IANA media type registry, the mime-db project and the freedesktop.org shared MIME database.