Extract text from ULD files
To convert your ULD file to another format, you need DIALux or other Data software.
To convert other file formats to the "Photometric Data Container" file type, you need software like DIALux or a similar tool.
A .ULD file is a Unified Luminaire Data container, the proprietary standard used by DIALux for distributing high-fidelity lighting fixture information. Unlike simple text-based photometric files (like IES or LDT), a .ULD acts as a comprehensive "digital twin" of a light fixture, encapsulating 3D geometry, mounting logic, textures, energy consumption data, and light distribution curves in a single Microsoft Compound File (OLE) structure.
The primary problem for users is the format's closed ecosystem. Manufacturers prefer .ULD because it prevents data tampering and ensures their fixtures look correct in simulations, but this creates a "black box" for designers using other software. You cannot open a .ULD file in AutoCAD, Revit, or AGi32 directly. If you need to perform calculations in non-DIALux software, you must convert the file to extracting the raw photometric data (IES or LDT). If you need the physical model for architectural rendering, the target format should be DWG, SAT, or OBJ. Without conversion tools, users are often forced to install the full DIALux suite just to export a simple 3D model or check a lumen output value.
Convert.Guru analyzes your ULD file, detects the exact format, and lets you read the text inside.
Users also converted LDT, ROLF, IES, PDF, DWG, RFA, CMBL, INDD, M3D and DLX 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 ULD converter.