Which MIME types are related to file extension ".vssm"?
The .vssm file extension is associated with 3 MIME types:
application/vnd.ms-visio.stencil.macroenabled.12, application/vnd.ms-visio.stencil.macroenabled.main+xml, application/vnd.visio.
A MIME type is a string that tells browsers and other tools how to handle a particular kind of file.
About .vssm Files
VSSM files are macro-enabled Visio stencil files that store a collection of reusable shapes and symbols for creating diagrams. They follow the Office Open XML format and can include embedded macros for added automation and interactivity.
Their MIME types reveal key aspects of their functionality:
- application/vnd.ms-visio.stencil.macroenabled.12 – Indicates an Office Open XML Visio stencil that supports macros.
- application/vnd.ms-visio.stencil.macroenabled.main+xml – Refers to the 2013 version with similar macro capabilities.
- application/vnd.visio – A generic MIME type associating the file with Visio applications.
VSSM files are mainly used in Microsoft Visio to supply a palette of standardized symbols for diagrams such as flowcharts, network layouts, and organizational charts. The macro functionality allows these shapes to automate repetitive tasks or perform custom actions when used in diagrams.
They are typically opened, viewed, and edited in Microsoft Visio (2013 or later versions). Other compatible Visio viewers or add-in tools may also support these files.
Based on information from FilExt.com, you can find further details at FilExt.com.
Relationship between file extension and MIME type
A file extension is a suffix at the end of a filename that indicates what type of file it is. File extensions help both users and operating systems identify what application should be used to open the file.
File extensions are typically separated from the filename by a period (dot) and consist of 2-4 characters, though they can be longer. For example, in the filename "document.pdf", ".pdf" is the file extension.
File extensions are closely related to MIME types, as they both serve to identify the format of a file. However, while MIME types are used primarily by web browsers and servers, file extensions are used by operating systems and applications.
Associated MIME types
application/vnd.ms-visio.stencil.macroenabled.12, application/vnd.ms-visio.stencil.macroenabled.main+xml, application/vnd.visio
FAQs
How do I open a .vssm file?
You can open .vssm files primarily with Microsoft Visio (version 2013 and later). Since this is a stencil file containing shapes rather than a finished diagram, you usually open it via the More Shapes > Open Stencil menu within Visio to add the shapes to your current workspace.
What is the difference between .vssx and .vssm files?
The main difference is that .vssm files are macro-enabled, meaning they contain embedded VBA (Visual Basic for Applications) code to automate tasks. A standard .vssx file is a macro-free stencil. If you do not need automation, the .vssx format is safer and more widely compatible.
Are .vssm files safe to open?
Because .vssm files contain macros, they pose a potential security risk if the file comes from an untrusted source. Macros can contain malicious code, so Microsoft Visio will typically ask for permission before enabling them. Only enable content if you trust the file's creator.
Can I view .vssm files without Microsoft Visio?
Yes, you can use Microsoft Visio Viewer to see the contents, or third-party tools like LibreOffice Draw. However, while LibreOffice can often display the shapes, it generally cannot execute the proprietary macros embedded within the file.
How do I convert a .vssm file to a standard .vssx file?
To convert the file, open it in Microsoft Visio, go to File > Save As, and select Visio Stencil (*.vssx) from the file type dropdown menu. This process strips out any macros, saving only the shapes and XML data.
Why does the file extension end in 'm'?
The 'm' at the end of Office Open XML extensions (like .docm, .xlsm, and .vssm) stands for macro. It distinguishes these files from standard XML-based files (ending in 'x') to alert users and software that the file may contain executable scripts.
What MIME type should be configured for serving .vssm files?
The specific MIME type for these files is application/vnd.ms-visio.stencil.macroenabled.12. Ensuring your web server sends this header helps browsers and operating systems recognize the file as a macro-enabled Visio stencil. You can learn more at mime-type.com.
General FAQ
What is a MIME type?
A MIME (Multipurpose Internet Mail Extensions) type is a standard that indicates the nature and format of a document, file, or assortment of bytes. MIME types are defined and standardized in IETF's RFC 6838.
MIME types are important because they help browsers and servers understand how to process a file. When a browser receives a file from a server, it uses the MIME type to determine how to display or handle the content, whether it's an image to display, a PDF to open in a viewer, or a video to play.
MIME types consist of a type and a subtype, separated by a slash (e.g., text/html, image/jpeg, application/pdf). Some MIME types also include optional parameters.
How do I find the MIME type for a file?
You can check the file extension or use a file identification tool such as file --mime-type on the command line. Many programming languages also provide libraries to detect MIME types.
Why can one extension have multiple MIME types?
Different programs and historical usage may assign various MIME identifiers to the same file format. Listing them together helps maintain compatibility across tools.