Delete all files of specific type (extension) recursively down a directory using a batch file

You can use wildcards with the del command, and /S to do it recursively.

del /S *.jpg

Addendum

@BmyGuest asked why a downvoted answer (del /s c:\*.blaawbg) was any different than my answer.

There's a huge difference between running del /S *.jpg and del /S C:\*.jpg. The first command is executed from the current location, whereas the second is executed on the whole drive.

In the scenario where you delete jpg files using the second command, some applications might stop working, and you'll end up losing all your family pictures. This is utterly annoying, but your computer will still be able to run.

However, if you are working on some project, and want to delete all your dll files in myProject\dll, and run the following batch file:

@echo off

REM This short script will only remove dlls from my project... or will it?

cd \myProject\dll
del /S /Q C:\*.dll

Then you end up removing all dll files form your C:\ drive. All of your applications stop working, your computer becomes useless, and at the next reboot you are teleported in the fourth dimension where you will be stuck for eternity.

The lesson here is not to run such command directly at the root of a drive (or in any other location that might be dangerous, such as %windir%) if you can avoid it. Always run them as locally as possible.

Addendum 2

The wildcard method will try to match all file names, in their 8.3 format, and their "long name" format. For example, *.dll will match project.dll and project.dllold, which can be surprising. See this answer on SU for more detailed information.

You can use this to delete ALL Files Inside a Folder and Subfolders:

DEL "C:\Folder\*.*" /S /Q

Or use this to Delete Certain File Types Only:

DEL "C:\Folder\*.mp4" /S /Q 
DEL "C:\Folder\*.dat" /S /Q 

I wrote a batch script a while ago that allows you to pick a file extension to delete. The script will look in the folder it is in and all subfolders for any file with that extension and delete it.

@ECHO OFF
CLS

SET found=0
ECHO Enter the file extension you want to delete...
SET /p ext="> "

IF EXIST *.%ext% (           rem Check if there are any in the current folder :)
  DEL *.%ext%
  SET found=1
)
FOR /D /R %%G IN ("*") DO (  rem Iterate through all subfolders
  IF EXIST %%G CD %%G
  IF EXIST *.%ext% (
    DEL *.%ext%
    SET found=1
  )
)

IF %found%==1 (
  ECHO.
  ECHO Deleted all .%ext% files.
  ECHO.
) ELSE (
  ECHO.
  ECHO There were no .%ext% files.
  ECHO Nothing has been deleted.
  ECHO.
)

PAUSE
EXIT

Hope this comes in useful to anyone who wants it :)