LinuxWhat is the WLD file format?
A .wld file is a plain-text georeferencing sidecar that maps a raster image - photograph, scanned map, or aerial tile - to real-world geographic coordinates. It contains exactly six lines, each holding a single decimal number that together define an affine transformation between pixel positions and ground coordinates:
- Line 1 - pixel width (X-scale: ground units per pixel in the X direction)
- Line 2 - rotation about the Y axis (0.0 for north-up images)
- Line 3 - rotation about the X axis (0.0 for north-up images)
- Line 4 - pixel height (Y-scale; negative by convention for top-down rasters)
- Line 5 - X coordinate of the upper-left pixel centre
- Line 6 - Y coordinate of the upper-left pixel centre
The .wld extension is the generic form of the world file standard introduced by Esri for ArcInfo in the early 1990s. Format-specific variants carry raster-matched extensions: .TFW for TIFF, .jgw for JPEG, .pgw for PNG, and .bpw for BMP - all follow identical rules. GDAL, QGIS, and ArcGIS Pro all recognise .wld as a valid alias.
The .wld file must share the same base name as its companion raster and reside in the same directory; deleting or moving it without the raster breaks georeferencing. Decimal values must use a dot separator regardless of system locale. GeoTIFF embeds equivalent georeferencing internally and does not require a sidecar, but .wld files remain in widespread use for legacy JPEG, PNG, and scanned map rasters.
Security & safety
RISK: LOWPlain-text file with 6 numbers; no executable code. Risk is data accuracy: an incorrect world file silently places the raster in the wrong location on the map.
Format details
in a nutshell- The Settlers II map file - Blue Byte's 1996 strategy game The Settlers II uses .wld (and .swd) for binary map/world files; completely unrelated to GIS.
- 3D World Studio terrain/world file - Some 3D game development tools (e.g. 3D World Studio) used .wld for world/scene description files.
Programs that open WLD files
Windows3 apps
NotePad++ text editor
Built-in Right-click > Open With > Notepad to inspect or manually edit the 6 transform values. 
ArcGIS Pro
Paid Add the companion raster (not the .wld) to a map; ArcGIS reads the .wld automatically for georeferencing. 
QGIS
Open-source Layer > Add Layer > Add Raster Layer - select the image file; QGIS reads the sidecar .wld automatically. Free. 
macOS1 app
Technical details
deep spec| Encoding | Plain ASCII text; six newline-separated decimal numbers, one per line |
| File size | Under 100 bytes (exactly six lines of text) |
| Coordinate transformation type | Affine (linear) 2D transformation encoding scale, rotation, and translation; no non-linear or rubber-sheet warping |
| Line 1 | X pixel size - ground units per pixel in the X direction (positive value) |
| Line 4 | Y pixel size - ground units per pixel in the Y direction; negative value encodes top-down raster orientation |
| Lines 5-6 | Easting and Northing (or longitude/latitude) of the upper-left pixel centre in the raster's coordinate reference system |
| Lines 2-3 | Rotation parameters; both are 0.0 for axis-aligned (north-up) rasters |
| Companion file requirement | Must share the same base filename as the raster image and reside in the same directory; mismatching breaks georeferencing |
| Decimal separator | Dot (`.`) required regardless of OS locale; comma separators are not accepted |
| Format-specific variants | `.tfw` (TIFF), `.jgw` (JPEG), `.pgw` (PNG), `.bpw` (BMP) follow the identical 6-line structure |
| CRS metadata | Stores only the affine pixel-to-coordinate transform; projection/CRS definition is held in a separate `.prj` sidecar or `.aux.xml` file |
| Superseded by | GeoTIFF (internal georeferencing); GDAL `.aux.xml` PAM format for complex CRS metadata |
| Released | Early 1990s with Esri ArcInfo; .wld as generic extension adopted in GDAL/QGIS era |
| Latest version | N/A (format is fixed 6-line specification, no versioning) |
| Open standard | Yes · royalty-free |
| Specification | www.loc.gov |
WLD conversions
Community Q&A
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