Extract text from GRN files
To convert your GRN file to another format, you need Granny 3D or other Game software.
To convert other file formats to the "3D Asset Container" file type, you need software like Granny 3D or a similar tool.
The .GRN file extension is primarily associated with Granny 3D, a powerful middleware toolkit developed by RAD Game Tools. These files are proprietary binary containers used extensively in the video game industry (appearing in titles like Civilization V, Grim Dawn, and Elder Scrolls Online) to store 3D meshes, vertex data, textures, and complex animation sequences using B-spline compression.
Because .GRN files are compiled for runtime efficiency rather than editing, they present significant friction for users. They are not interchangeable standard formats; you cannot simply double-click to open them in Adobe Photoshop or import them directly into Blender without specialized plugins. The internal structure often changes between different versions of the Granny SDK, meaning a tool that opens a file from one game may crash when opening a file from another. This "version locking" is a major hurdle for modders and archivists.
For 3D modeling and game modding, the best conversion targets are FBX (Filmbox) or OBJ (Wavefront), which allow the geometry and skeletal data to be edited in standard suites like Autodesk 3ds Max. For simply viewing the contents without editing, converting to a lightweight GLB or using the standalone Granny Viewer is recommended. In rare cases (approx. 7%), a .GRN file may be a data file for the legacy Girin 2D graphics engine, which requires entirely different parsing logic.
Convert.Guru analyzes your GRN file, detects the exact format, and lets you read the text inside.
Users also converted GR2, BIK and ZRB files.
The history of Convert.Guru began over 25 years ago in California with Tom Simondi’s file-format database. A former contributor to Space Shuttle development and a software pioneer of the 1980s, Simondi established a trusted resource for file type analysis that was even referenced by Microsoft Windows XP. Today, we use modern technology to process and convert thousands of file formats while continually improving our GRN converter.