This page shows the different ways to start FreeCAD and the most important configuration features.

Starting FreeCAD from the Command line

FreeCAD can be started normally, by double-clicking on its desktop icon or selecting it from the start menu, but it can also be started directly from the command line. This allows you to change soem of the default startup options.

Command line options

The command line options are subject of frequent changes, therefore it is a good idea to check the current options by typing:

FreeCAD --help

From the response you can read the possible parameters:

FreeCAD [options] File1 File2 .....
Allowed options:  

Generic options:
 -v [ --version ]      print version string
 -h [ --help ]         print help message
 -c [ --console ]      start in console mode
 --response-file arg   can be specified with '@name', too
 -l [ --write-log ] arg    write a log file to default location(Run FreeCAD --h to see default location)
 --log-file arg            Unlike to --write-log this allows to log to an arbitrary file
 -u [ --user-cfg] arg      User config file to load/save user settings
 -s [ --system-cfg] arg    System config file to load/save system settings
 -t [ --run-test ] arg     test level
 -M [ --module-path ] arg  additional module paths
 -P [ --python-path ] arg  additional python paths 

EX: (Windows)

"C:\Program Files\FreeCAD 0.14\bin\FreeCAD.exe" -M "N:\FreeCAD\Mod\Draft" -M "N:\FreeCAD\Mod\Part" -M "N:\FreeCAD\Mod\Drawing" -u "N:\FreeCAD\Config\user.cfg" -s "N:\FreeCAD\Config\system.cfg" 

Response and config files

FreeCAD can read some of these options from a config file. This file must be in the bin path and must be named FreeCAD.cfg. Be aware that options specified in the command line override the config file!

Some operating system have very low limit of the command line length. The common way to work around those limitations is using response files. A response file is just a configuration file which uses the same syntax as the command line. If the command line specifies a name of response file to use, it's loaded and parsed in addition to the command line:

FreeCAD @ResponseFile.txt 


FreeCAD --response-file=ResponseFile.txt 

Hidden options

There are a couple of options not visible to the user. These options are e.g. the X-Window parameters parsed by the Windows system:

  • -display display, sets the X display (default is $DISPLAY).
  • -geometry geometry, sets the client geometry of the first window that is shown.
  • -fn or -font font, defines the application font. The font should be specified using an X logical font description.
  • -bg or -background color, sets the default background color and an application palette (light and dark shades are calculated).
  • -fg or -foreground color, sets the default foreground color.
  • -btn or -button color, sets the default button color.
  • -name name, sets the application name.
  • -title title, sets the application title.
  • -visual TrueColor, forces the application to use a TrueColor visual on an 8-bit display.
  • -ncols count, limits the number of colors allocated in the color cube on an 8-bit display, if the application is using the QApplication::ManyColor color specification. If count is 216 then a 6x6x6 color cube is used (i.e. 6 levels of red, 6 of green, and 6 of blue); for other values, a cube approximately proportional to a 2x3x1 cube is used.
  • -cmap, causes the application to install a private color map on an 8-bit display.

Running FreeCAD without Graphical User Interface

FreeCAD is usually built with two executables: a GUI capable one called FreeCAD, and a command line only FreeCADCmd. FreeCAD can be used in console mode using the "-c" switch, this is the default behaviour of FreeCADCmd:

FreeCAD -c

from the command line. In console mode, no user interface will be displayed, and you will be presented with a python interpreter prompt. From that python prompt, you have the same functionality as the python interpreter that runs inside the FreeCAD GUI, and normal access to all modules and plugins of FreeCAD, excepted the FreeCADGui module. Be aware that modules that depend on FreeCADGui might also be unavailable.

Python scripts/FreeCAD macro files can be specified as command line arguments to either of the executables mentioned above.

The Config set

On every Startup FreeCAD examines its surrounding and the command line parameters. It builds up a configuration set which holds the essence of the runtime information. This information is later used to determine the place where to save user data or log files. It is also very important for post postmortem analyzes. Therefore it is saved in the log file.

User related information

User config entries
Config var name Synopsis Example M$ Example Posix (Linux)
UserAppData Path where FreeCAD stores User Related application data. C:\Documents and Settings\username\Application Data\FreeCAD /home/username/.FreeCAD
UserParameter File where FreeCAD stores User Related application data. C:\Documents and Settings\username\Application Data\FreeCAD\user.cfg /home/username/.FreeCAD/user.cfg
SystemParameter File where FreeCAD stores Application Related data. C:\Documents and Settings\username\Application Data\FreeCAD\system.cfg /home/username/.FreeCAD/system.cfg
UserHomePath Home path of the current user C:\Documents and Settings\username\My Documents /home/username

Command line arguments

User config entries
Config var name Synopsis Example
LoggingFile 1 if the logging is switched on 1
LoggingFileName File name where the log is placed C:\Documents and Settings\username\Application Data\FreeCAD\FreeCAD.log
RunMode This indicates how the main loop will work. "Script" means that the given script is called and then exit. "Cmd" runs the command line interpreter. "Internal" runs an internal script. "Gui" enters the Gui event loop. "Module" loads a given python module. "Cmd"
FileName Meaning depends on the RunMode
ScriptFileName Meaning depends on the RunMode
Verbose Verbosity level of FreeCAD "" or "strict"
OpenFileCount Holds the number of files opened through command line arguments "12"
AdditionalModulePaths Holds the additional Module paths given in the cmd line "extraModules/"

System related

User config entries
Config var name Synopsis Example M$ Example Posix (Linux)
AppHomePath Path where FreeCAD is installed c:/Progam Files/FreeCAD_0.7 /user/local/FreeCAD_0.7
PythonSearchPath Holds a list of paths which python search modules. This is at startup can change during execution

Some libraries need to call system environment variables. Sometimes when there is a problem with a FreeCAD installation, it is because some environment variable is absent or set wrongly. Therefore, some important variables get duplicated in the Config and saved in the log file.

Python related environment variables:


OpenCascade related environment variables:

  • CSF_MDTVFontDirectory
  • CSF_MDTVTexturesDirectory
  • CSF_UnitsDefinition
  • CSF_UnitsLexicon
  • CSF_StandardDefaults
  • CSF_PluginDefaults
  • CSF_SHMessage
  • CSF_XCAFDefaults
  • CSF_GraphicShr
  • CSF_IGESDefaults
  • CSF_STEPDefaults

System related environment variables:

  • PATH

Build related information

The table below shows the availible informations about the Build version. Most of it comes from the Subversion repository. This stuff is needed to exactly rebuild a version!

User config entries
Config var name Synopsis Example
BuildVersionMajor Major Version number of the Build. Defined in src/Build/ 0
BuildVersionMinor Minor Version number of the Build. Defined in src/Build/ 7
BuildRevision SVN Repository Revision number of the src in the Build. Generated by SVN 356
BuildRevisionRange Range of differnt changes 123-356
BuildRepositoryURL Repository URL
BuildRevisionDate Date of the above Revision 2007/02/03 22:21:18
BuildScrClean Indicates if the source was changed ager checkout Src modified
BuildScrMixed Src not mixed

Branding related

These Config entries are related to the branding mechanism of FreeCAD. See Branding for more details.

User config entries
Config var name Synopsis Example
ExeName Name of the build Executable file. Can diver from FreeCAD if a different main.cpp is used. FreeCAD.exe
ExeVersion Over all Version shows up at start time V0.7
AppIcon Icon which is used for the Executable, shows in Application MainWindow. "FCIcon"
ConsoleBanner Banner which is prompted in console mode
SplashPicture Name of the Icon used for the Splash Screen "FreeCADSplasher"
SplashAlignment Alignment of the Text in the Splash dialog Left"
SplashTextColor Color of the splasher Text "#000000"
StartWorkbench Name of the Workbech which get started automaticly after Startup "Part design"
HiddenDockWindow List of dockwindows (separated by a semicolon) which will be disabled "Property editor"
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