What is a UML file?
A .UML file is primarily a Unified Modeling Language diagram. Software developers use these diagrams to map out system architecture, workflows, and object structures. These files typically contain structural and behavioral models created using tools like StarUML or PlantUML. They are usually saved as plain text or structured XML.
Less commonly, a .UML file might belong to a video game. It can serve as a character file for the game Dungeon Siege by Gas Powered Games or as a package data file for the Unreal game engine.
How to open UML files?
Because the .UML extension has multiple possible meanings, we recommend using viewer.online/uml. This tool analyzes .UML files to identify their exact format and creator software, shows which programs can open the file, and usually previews it.
Software and tools
You can open standard .UML diagrams with specialized modeling applications such as StarUML, Enterprise Architect, or the Eclipse IDE with modeling plugins. If the file is plain text, like those generated by PlantUML, any text editor like Visual Studio Code or Notepad++ can read the source code.
Best practices and troubleshooting
If you need to share a diagram with non-developers, you should convert the .UML file to a standard image format. You can convert .UML to .PNG, .JPEG, or .PDF. We recommend convert.guru for fast and reliable file conversion.
Summary
In most cases, .UML files use the known XML format. Because of this, viewer.online/uml can safely open and display them online, eliminating compatibility problems.