81

I need a way to rename all files in folders and subfolders to lowercase.

I'd like to know if there is a way to do that using only windows (XP or 7)

6
  • windows doesn't differentiate between small and upper caps as unix does. maybe, if you said, why you need this, it would help in solving the problem.
    – Rook
    Nov 4, 2009 at 0:47
  • 1
    @Idigas. Sorry, but since NTFS, filenames have been case sensitive. See support.microsoft.com/kb/100625 Nov 4, 2009 at 6:49
  • Just great. Take a bad idea and spread it further. What a support nightmare when someone sends a file and a fat finger mistake means they sent "Answers.dat" and the incoming process expects "answers.dat". There's just no good reason for those two names to be considered 'different'.
    – David
    Nov 4, 2009 at 12:45
  • 2
    @David, for example Java actually requires case-sensitive file names. That can yield a lot of trouble on non-case-sensitive file systems.
    – Arjan
    Nov 4, 2009 at 17:26
  • 10
    I know this is old, but I wanted to clarify a misconception here. While NTFS supports case sensitivity, the Windows OS DOES NOT differentiate!
    – geo
    Jan 23, 2013 at 20:37

13 Answers 13

157

Go to the directory and run the following command:

for /f "Tokens=*" %f in ('dir /l/b/a-d') do (rename "%f" "%f")

Here is the break-down in case someone wants to modify/improve :

  • for /f - For every line
  • "Tokens=*" - Process each item in every line.
  • %f in (...) - %f is your variable name for every item.
  • dir - lists every file and subdirectory in a directory.
  • /l - (parameter for dir) Uses lowercase.
  • /b - (parameter for dir) Uses bare format, only the file/directory names, no size, no headers.
  • /a-d - (parameter for dir) Do not list directories. (a stands for attribute, - stands for not and d stands for directory).
  • rename "%f" "%f"- rename the file with its own name, which is actually lowercased by the dir command and /l combination.
13
  • 8
    Recursive version: for /f "Tokens=*" %f in ('dir /l/b/a-d/s') do (rename "%f" "%f") (added /r to dir).
    – Sawny
    Feb 13, 2013 at 18:20
  • 3
    this is just briliant
    – Shir Gans
    Apr 4, 2013 at 18:27
  • 4
    The recursive version didn't work for me -- rename complained about the command being in an invalid format. Turns out the /s caused the second file to be listed as an absolute path and using filename expansion (%~nxf) gave me the original, uppercase filename. Ended up just manually recursing.
    – Dogmatixed
    Aug 7, 2013 at 1:21
  • 3
    This is a very nice answer; to the point, no external programs needed, nice and small command, no batch file complicated-ness needed. Oct 10, 2013 at 15:44
  • 3
    Can it be modified to change lowercase to uppercase?
    – Chucky
    Jan 7, 2016 at 16:52
22

spacetornado Renamer is a Windows program that renames mass amounts of files in batches. You can search and replace text, remove a certain number of characters, change the case to lower, upper or First Letter Capital, and add text to the beginning or end (append/prepend) of every filename

enter image description here

7
  • 1
    Please give me the reason for down vote ?
    – joe
    Nov 4, 2009 at 8:52
  • 5
    People rarely explain, unfortunately :/
    – Gnoupi
    Nov 4, 2009 at 9:02
  • 7
    I guess the downvote was because the OP wanted a solution that worked without any additional software. And I guess the downvote wasn't explained because some people are prone to deal out revenge downvotes.
    – innaM
    Nov 4, 2009 at 12:20
  • The GUI is a little funky but it does the job better than several other renamers that I've seen out there.
    – jcollum
    Nov 23, 2010 at 21:46
  • 1
    It did what it did, when I needed recursive renaming for cleaning up files from a Linux FTP server... however, needed to run it as Admin before it worked properly. Feels like an old an un-maintained program :)
    – Nelson
    Oct 12, 2015 at 9:28
22

Since Windows 7 you could use PowerShell for those tasks

Get-ChildItem "C:\path\to\folder" -recurse | 
  Where {-Not $_.PSIsContainer} | 
  Rename-Item -NewName {$_.FullName.ToLower()}

- Choose your root folder
- all files inside root folder and subfolders are renamed
- folder names are excluded with Where {-Not $_.PSIsContainer} |

3
  • 1
    Won't work...Powershell doesn't allow renaming something to the same name...even if the case is different.
    – Agile Jedi
    Jul 1, 2021 at 16:13
  • I can confirm that this does not currently work, it throws this error: Rename-Item : Source and destination path must be different. Dec 8, 2021 at 15:51
  • Although Its working in windows-10-home Apr 25 at 6:45
10

Here is a proper recursive command line solution using only native cmd.exe commands that actually works. I believe it is the simplest possible native solution:

for /r %D in (.) do @for /f "eol=: delims=" %F in ('dir /l/b/a-d "%D"') do @ren "%D\%F" "%F"

If you are willing to go beyond native cmd.exe commands, then another option is my JREN.BAT regular expression renaming utility that supports options to convert names to upper or lower case. It is pure script (hybrid JScript/batch) that runs natively on any Windows machine from XP onward - no 3rd party exe files needed. Full documentation is built in - accessed from the command line via jren /?, or jren /?? if you want paged output.

With JREN, the recursive solution is as simple as:

jren "^" "" /s /l
5
  • 1
    Works great. FYI remove the /a-d switch and it will also lowercase the folder names too.
    – Keith
    Jul 18, 2017 at 14:50
  • Tried saving it as a batch file and popped it in system32 so I could run it anytime with a single command. Results in this: " D"') was unexpected at this time. Running it as a direct command works fine, just doesn't work when run as a batch file. Not sure as to how to make it work as a batch file, but thought I'd give heads up to the issue.
    – Don Cullen
    Apr 12, 2018 at 17:49
  • 1
    @DonCullen - It is standard syntax that FOR variable percents must be doubled when using FOR within a batch script. So %D must change to %%D, and %F to %%F if you put the command within a batch script.
    – dbenham
    Apr 12, 2018 at 18:22
  • Always learning something new everyday. Thanks!
    – Don Cullen
    Apr 12, 2018 at 21:29
  • This worked for me in Command Line. Idk why it didn't work in PowerShell
    – OG Sean
    Nov 24, 2019 at 22:43
8

"Recursive" version of the accepted answer (that works*)

for /f "Tokens=*" %f in ('cmd /c "echo %cd%& dir /l/b/ad/s"') do (for /f "Tokens=*" %g in ('dir /l/b/a-d "%f"') do (rename "%f"\"%g" "%g"))


The first loop

for /f "Tokens=*" %f in ('cmd /c "echo %cd%& dir /l/b/ad/s"')

Gets a list of the absolute paths of all the directories inside the current (including it):

C:\Foo>

  • C:\Foo\TO.txt

  • C:\Foo\Bar\LOWER.txt

  • C:\Foo\Bar\Baz\CASE.txt


The second loop

for /f "Tokens=*" %g in ('dir /l/b/a-d "%f"') do (rename "%f"\"%g" "%g")

Gets a list of all the file names (or file and directory names if you take out the /a-d switch) inside each of the absolute paths found by the first loop, and converts the name of these files to lowercase.

  • C:\Foo\TO.txt

  • C:\Foo\Bar\LOWER.txt

  • C:\Foo\Bar\Baz\CASE.txt


* it needs two loops because the second argument to rename must be a file name and not an absolute path (as the one obtained by the /s switch).

5
  • Why do you have cmd /c "echo %cd%& in the first for? It is completely unnecessary.
    – DavidPostill
    May 6, 2016 at 17:05
  • @DavidPostill echo %cd% is there to add the current folder to the list of absolute paths; and cmd /c makes & work to combine commands. I'm a total noob regarding Windows Batch Scripting; if you know of a better way, feel free to improve the answer!
    – wc.matteo
    May 7, 2016 at 11:19
  • Excellent job for a noob. Yours was the first native cmd.exe command line solution that actualy works, except it fails when a name begins with space or semicolon.The accepted answer suffers the same problem. See my answer for a simpler answer that also works with leading space or semicolon.
    – dbenham
    Jul 21, 2016 at 22:13
  • Can this be modifies to convert lower to caps?
    – Rishav
    Feb 18, 2018 at 4:08
  • First one that actually worked. Thanks! Mar 24, 2020 at 16:38
6

My personal favorite batch file-renaming utility is Cylog's WildRename. Among many other features, it can change the case of filenames. The best thing about WildRename is probably that it supports regular-expressions!

1
  • THIS is the right app, after installation in 10 secs. I configured and renamed recursively a remote folder (mapped for convenience). Jan 24, 2019 at 8:54
3

You could use a "character replacement" strategy...

set Name=%Name:A=a%
set Name=%Name:B=b%
set Name=%Name:C=c%

...and so on, for letters A-Z. You could probably implement it in the form of a FOR loop.

2

Powershell

Navigate to the dir and run:

dir | Rename-Item -NewName { $_.Name.ToLowerInvariant() }

I have verified that this works. Found here: http://www.hanselman.com/blog/PennyPinchingVideoMovingMyWebsitesImagesToTheAzureCDNAndUsingACustomDomain.aspx

1

http://www.dostips.com/DtCodeCmdLib.php#Function.toLower gives a simple function that you should be able to include and call from a batch file.

So have the batch file iterate over the folders/filenames, and call this function to generate the lowercase version of the name.

1

From http://windowsitpro.com/articles/index.cfm?articleid=81612:

Using only standard commands, I have scripted LwrCase.bat and LwrCase_Folder.bat, to rename a file name to lower case, or rename all file names in a folder to lower case.

To rename a file name to lower case, use:

[call] LwrCase FullyQualifiedFileName

Where FullyQualifiedFileName is the fully qualified file name to be renamed.

To rename all the files names in a directory, use:

[call] LwrCase_Folder FullyQualifiedDirectoryName [/S]

where FullyQualifiedDirectoryName is the fully qualify folder path, and /S is an optional parameter that will also rename files names in all sub-folders.

NOTE: LwrCase.bat makes use the the /L switch of the DIR command, which returns lower case names.

LwrCase.bat contains:

@echo off
if {%1}=={} @echo Syntax: LwrCase FullyQualifiedFileName&goto :EOF
if not exist %1 @echo LwrCase - %1 NOT found.&goto :EOF
setlocal
for /f "Tokens=*" %%a in ('@echo %~a1') do (
 set file=%%a
)
if /i "%file:~0,1%" EQU "d" @echo LwrCase - %1 is NOT a file.&endlocal&goto :EOF
for /f "Tokens=*" %%f in ('dir %1 /L /b /a /a-d') do (
 Rename %1 "%%f"
)
endlocal

LwrCase_Folder.bat contains:

@echo off
if {%1}=={} @echo Syntax: LwrCase_Folder FullyQualifiedDirectoryName&goto :EOF
if not exist %1 @echo LwrCase_Folder - %1 NOT found.&goto :EOF
setlocal
for /f "Tokens=*" %%a in ('@echo %~a1') do (
 set folder=%%a
)
if /i "%folder:~0,1%" NEQ "d" @echo LwrCase_Folder - %1 is NOT a folder.&endlocal&goto :EOF
pushd %1
set sw=/B /A /A-D
if /i {%2}=={/S} set sw=%sw% %2
for /f "Tokens=*" %%f in ('dir %sw%') do (
 call LwrCase "%%f"
)
popd
endlocal
1

The best program for doing this in Windows is Bulk Rename Utility. It is a mans tool. You can even use regex to rename files and/or folders. It also has shell integration (so you can execute from explorer with a right click) which is very nice. 64 bit and 32 bit versions available.

1

The accepted answer to this question, by loftysnake, works for the current directory but does not search subfolders.  Sawny suggested a simple modification to loftysnake’s answer to make it recursive, but it doesn’t work, because, while the rename command allows you to specify a drive and path with filename1 (the source), filename2 (the destination) must be just a filename.  To quote the help (/?) message,

… you cannot specify a new drive or path for your destination file.

But move works where rename does not, so you can recursively rename files to lowercase with this command:

for /f "Tokens=*" %f in ('dir /l/b/a-d/s') do (move /y "%f" "%f")

because it turns out that Move can cope with directory paths.

The above command works when typed directly into the Command Prompt (CMD.EXE).  If you want to do this from within a batch (.BAT) file, you must double the % characters:

for /f "Tokens=*" %%f in ('dir /l/b/a-d/s') do (move /y "%%f" "%%f")

And you can probably leave off the parentheses and the /y and say just do move ….

3
  • If you're going to re-post information that others have already posted, you should identify the original author(s) and link to their post(s). May 30, 2017 at 17:09
  • Sorry, but I was pointing out that move worked where rename does not, and I think I am the only one who has suggested the use of the move command here. I simply took @loftysnake and @sawny s suggestions, and hopefully improved them a wee bit.
    – Adrian
    May 30, 2017 at 18:09
  • That’s weird; I thought somebody else had mentioned move, but I can’t find it now. May 30, 2017 at 19:13
0

Recursive solution. Put this into a recursiverename.cmd file..

for /f "Tokens=*" %%f in ('dir /l/b/a-d') do (rename "%%f" "%%f")
for /r /d %%x in (*) do (
    pushd "%%x"
    for /f "Tokens=*" %%f in ('dir /l/b/a-d') do (rename "%%f" "%%f")
    popd
)

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