Why does GIMP start up so slow on my machine?

If this happens to you when the splash screen gets to "Loading Data Files - Fonts", then there are several workarounds to this slowdown.

To analyze the slowdown, you may add the --verbose parameter to GIMP to better analyze startup problems.

The article Slow GIMP startup : Graphics advises :

This used to happen to me too. Some kind-soul told me that there in the c:\documents and settings\user-name\ directory, there will be a ..fonts-cache1 file. Delete that cache and re-start GIMP. First time it takes a while to make that fonts-cache again, but from 2nd time it should be pretty normal.

Note that on newer systems (Windows 7 & 10) this folder moved to C:\Users\<username>\AppData\Local\fontconfig. A quick way to get there is typing: Win+r, and entering %appdata%/../local/fontconfig (or write the same in the address line of a file-explorer window).

Another advise is :

I created a shortcut with the command parameter --no-fonts and it started very quickly.

The GIMP FAQ says :

The GIMP takes too long to load - how can I speed it up?

The main things are to make sure you are running at least version 1.0, and make sure you compiled with optimization on, debugging turned off, and the shared memory and X shared memory options tuned on.

Or, buy a faster system with more memory. 8^)

If it's still too slow for you, the easiest speedup is to invoke the GIMP with the "--no-data" option. This prevents the GIMP from loading patterns, brushes, and similar resources when it starts. You may benefit slightly from the "--no-splash" option as well; you might want to time that one to see if it really helps enough to be worthwhile.

If the problem lies in one or more extensions, the only solution is to uninstall these extensions. The extensions are found in the folder GIMP is installed in (usually Program Files), inside C:\Program Files\GIMP-2.0\lib\gimp\<version>\plug-ins. Just rename the extension file to .old or something, for example script-fu.exe to script-fu.exe.old. The easiest way to get rid of all the extensions is to rename the entire plug-ins folder.

Selected answer worked for me.

However, had to use different steps.

Using Windows 7
Using Gimp 2.8

=== Step 1.   Diagnose ===

1. Navigate to C:\Program Files\GIMP 2\bin
2. Shift + Right Click -> "Open Command Window Here"
   (click the empty space of the folder, not an icon)
3. Type gimp-2.8.exe --verbose
4. Watch the Gimp console that pops up :
   see what is taking the longest to load.
   

For me, it would hang on "Loading fonts" for 15 seconds,
every single time I launched.

5. For a quick process of elimination :
   close Gimp + type this into Windows Command Prompt
   
   gimp-2.8.exe --verbose --no-fonts

n o t e :
calling gimp-2.8.exe only works if your console's path
is the same as the gimp-2.8.exe directory.

=== Step 2.   Locate Gimp's font cache ===

C:\Users\User_Name\ had no files resembling ".fonts-cache1"
C:\Users\User_name\.gimp-2.8 had nothing font related except an empty fonts folder

If you do find it there : follow the steps of the selected answer above.

On my machine :
the font folder where Gimp 2.8 stores its font cache
is located in : C:\Users\User_Name\AppData\Local\fontconfig

    h i n t :
    click Windows start button, type %appdata%/../local then press enter

=== Step 3.   Verify this is the right folder ===

Inside of C:\Users\User_Name\AppData\Local\fontconfig
there should be a folder called cache.
Rename it to anything else : example cache.backup .

1. Stay in the ..\AppData\Local\fontconfig directory.
2. Run Gimp.
3. See if it generates a new cache folder.

If so, you definitely know that this is Gimp's font cache folder.

=== Step 4.   Hopefully it's fixed; let's find out ===

The last step hid Gimp's cache,
and Gimp regenerated a new one.

If you close Gimp + reopen it,
it should open significantly faster
(hopefully this was the root of your problem!)

I copied all files in C:\Program Files\GIMP 2\lib\gimp\2.0\plug-ins to a new folder named Unused, also inside plug-ins.

Started up Gimp: ~1 second compared to ~40 seconds previously. I then copied frequently used ".exes" into the plug-ins folder. Now Gimp starts in ~3 seconds.