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FME Filenames and Locations

Dataset Locations

Click on readers and writers in the Navigator and select Open Containing Folder (Ctrl + O).

File Extensions

FME has many associated file extensions. The default locations are listed here but can also change depending on where you installed FME.

Filename/File Extension


Default Location


Contains the names and descriptions of all predefined coordinate systems.

FME installation folder



Custom Formats

My Documents\FME\Formats



FME mapping file (FME Quick Translator)


.fmf FME metafile - Used to configure format definitions. FME installation folder, metafile subfolder
.fmelic FME license file User-defined


FME Viewspace - Used by the FME Data Inspector to load a predefined view.




FME Workbench workspace


My Documents\My FME Workspaces



FME Workbench template - Used to package an FME workspace and source data.

This extension is also used for templates downloaded from FME Hub.

My Documents\FME\Templates


Custom transformers

My Documents\FME\Transformers


User-defined transformer list

My Documents\FME\TransformerCategories


FME catalog file

Contains instructions to direct Workbench to download a specified resource from FME Knowledge Since these files contain only instructions (XML), they are small in size.

.fps FME Feature Store (FFS) pointcloud sidecar file - Used to store FFS point cloud data.  
.frs FME Feature Store (FFS) raster sidecar file - Used to store FFS raster data.  
.fsi FME Feature Store (FFS) spatial index file - Used to store the spatial index for FFS datasets.  

.gdc, .gsb, .las, .los, .mrt, .txt, .csv

Coordinate system and grid data files




custom coordinate system definitions

FME installation folder, Reproject subfolder


This file is automatically loaded and made available to each FME session, to allow sites to add their own coordinate systems. It contains a series of COORDINATE_SYSTEM_DEF, DATUM_DEF, ELLIPSOID_DEF, and UNIT_DEF lines that define additional, site-specific coordinate systems.

You can edit these files to add your own definitions.

Reproject subfolder under the FME installation folder

Defining Custom Units