What is an FLD file?
An .FLD file is a generic extension used for various field data formats depending on the software that created it. Most commonly, it stores electromagnetic field simulation data for engineering software like Ansys HFSS or CST Studio Suite. In other industries, an .FLD file acts as an agricultural field data container for the AgGateway ADAPT framework (often formatted as a standard ZIP archive), or as a thermodynamic fluid data file for NIST REFPROP.
Other systems also rely on this extension. It can store surveying instrument field data for Leica, Trimble, and Carlson Software, scientific computing data for AVS/Express or SCIRun, or database definitions for Actian Zen. In the gaming world, an .FLD file functions as a YSFLIGHT Field File for the flight simulator from YSFLIGHT.com.
How to open FLD files?
Because an .FLD file has multiple possible meanings, it is difficult to guess which program you need. We recommend using viewer.online/fld to identify the actual format of the user's file. viewer.online/fld can analyze .FLD files to identify the exact format and creator software, inspect the file structure, extract readable text, and check whether an online preview is available.
If you already know the file type, you can use the original software. For example, use Ansys HFSS for engineering simulations, or standard archiving tools like 7-Zip if the file is an agricultural data container.
Best practices and troubleshooting
Do not change the file extension to force the file to open. This will not change the file format and can corrupt the internal data. If you are importing surveying .FLD files into CAD software, ensure that you have the correct manufacturer plugin installed so the software can translate the field codes accurately.
Summary
viewer.online/fld is useful for identifying, inspecting, and understanding .FLD files without installing software or dealing with compatibility problems.