ArcGIS BIL world file
File type: GIS, GPS navigation and map file
The bilw file extension identifies a world file used with a raster in Band Interleaved by Line (BIL) format.
The bilw file stores georeferencing information that allows ArcGIS to place the associated BIL raster correctly on a map.
File type category:
GIS, GPS navigation and map file
Date updated: October 2, 2026
ArcGIS, Esri's geographic information system (GIS) software, uses the bilw file as a companion to a BIL raster. The file does not contain the raster's pixel values or imagery.
A BIL world file contains six text values describing the raster's pixel size, rotation and map position. ArcGIS reads these values together with the matching BIL raster and its supporting files to determine where the raster belongs geographically.
The format is used by ArcGIS on Microsoft Windows and Microsoft Windows Server operating systems.
Open the associated BIL raster in ArcGIS on Microsoft Windows. Keep the bilw file in the same folder as the matching BIL raster so ArcGIS can detect and apply its georeferencing automatically.
A bilw file can also be viewed as plain text, but it is a supporting georeferencing file rather than a standalone image or map.
A bilw file does not contain image data, so it is not normally converted by itself. To convert the complete dataset, open the associated BIL raster in ArcGIS and export it to another raster format, preserving or defining the coordinate system and georeferencing during export.
If only the georeferencing is needed in another format, ArcGIS can create the appropriate supporting georeferencing data when the raster is exported.
Software applications that handle other tasks involving bilw files:
Microsoft Windows
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