Please describe what you mean, respectively what you really do with Mp3tag when you use the term “change” in your post above.
There are so many ways to change something with the help of Mp3tag, so I am not able to guess what has really happened and how.
It is rather uncommon to get the file extension renamed.



look this



Oh, what a nice small picture, where is the magnifying glass?
I see a detail of Mp3tag 2.46a file list view showing a filename with correct “.mp3” extension.
I can not see what you want to show me. What is the image telling me?




i can only upload 200 kb soory what can i do…


look and this


Give it up! Good night.



how did you did that???


Don’t upload bmp, convert it first to JPG or PNG with an image tool like IrfanView.

Or use a screenshot tool like to make screenshots.


How did YOU do the renaming of your mp3 file?
The screenshots do not tell so much about the ACTION, which you use to rename the filename.
You are using an action, assumingly, don’t you?
It looks like you are using an action, because one of your screenshots, file “________.bmp”, shows a menu from where you execute some predefined action script, so that the filename, including the file extension, will be set to all uppercase, as shown in screenshot file “__________.bmp”.
Now let us see the type name of the action and the parameters of this action, respectively of all actions from the entire envolved action group, which stands behind the name from the selected menu item.



hi in the action menu i have programed to replace all latin charachters to greek one by one

for example
m to ν
e to ε
s to σ
w to ω
r to ρ
t to τ
d to δ
b to β

and that changes and the extension…


dj 8adam-e!, your screenshot shows not all of the involved actions, and sadly to say, I am not very experienced in reading greek language. When ever possible for you, please try to communicate in english language and offer Mp3tag screenshot in english skin too.

The partly shown list of actions have simple “Replace” actions.

The first action is a modified “Replace (only as whole word)”.
Did you ever check the result of this action?
I think this action will do nothing.

Assumingly there is a file in the filesystem having this filename “This is my filename.MΠ3”, then Mp3tag will not respect this file, because of the bad file extension. Although the file data might be internally of type MP3, other player applications might not accept such a filename, Mp3tag simply does not show such a badly named file in it’s file list view.
Therefore this first action is needless.

The replace modifier “only as whole word” is needless too, because a “whole word” is defined as a sequence of non space letters which are delimited by at least one space character or the word is the first or last word in a line of words.
Having a string of “.MΠ3” this looks not to be a “whole word”.
Same in the string “This is my filename.MΠ3” the substring “.MΠ3” will not be a “whole word”.

And even better, looking at the complete filebasename (filerootname.fileextension) the dot character seems to be handled in different ways by Mp3tag.
Having the filename “ my filename.mp3” the “Replace” action can replace “” with “is is”, but not “e.mp3” with “e.mp4”.

Nevertheless “Replace” action is able to replace “mp3” with “mp4”, giving the filename “ my filename.mp4”

Having the filename “” the “Replace” action can replace “.” with “” (i. e. nothing, that means remove all dots), which results into the filebasename “Thisismyfilename.mp3”.
You see that Mp3tag has saved the fileextension.

Mp3tag respects the dot in different ways. The right most dot is treated as the delimiter between the filerootname and the fileextension. All other dots at the left side of this one name delimiter dot are treated as simple characters of the filerootname (and can be object of the replace action).

The bad side effect of the “Replace” action when working on the pseudo tag-field “_FILENAME” is the case as mentioned above, that the given file extension can be changed accidentally.
Having a filename “jump3money.mp3” which should be named to “jump4money.mp3” will be
changed to “jump4money.mp4” when using “Replace” action and replace “mp3” with “mp4”.

I tend to mark this as a bug of the “Replace” action when working on pseudo tag-field “_FILENAME”.
At least there is a trap for the user to accidentally change the fileextension to make the file unusable. This behaviour should be revised.

The third action from your list of “Replace” actions is needless (from “.mp3” to “.mp3”).
All other shown actions from the screenshot are looking fine.

Such a filename “This is my filename.MΠ3” needs to be renamed from outside of Mp3tag by a specific file renamer tool (e. g. command REN on the commandline, Windows Explorer, Total Commander or other tools).

Try the attached cmd file, it might be possible, that it can rename the “*.MΠ3” files - no guarantee at all. First remove the “.txt” extension. Copy the cmd file into the root folder of the foldertree which contains the *.MΠ3 files and run it.
Rename_M__3_to_mp3.cmd.txt (241 Bytes)


Rename_M__3_to_mp3.cmd.txt (241 Bytes)

[X] Ersetzen mit Regulärem Ausdruck in _FILENAME

maybe this picture will help you more…


and this…


You missed the step where you change the lower “p” to lower “π”.
You missed the step where you change the mixed case letters into upper case.

Please send us the entire “.mta” file which you have used in your screen demo.
You can find this file in the folder %APPDATA%\Mp3tag\data\actions</b>
See also:
freedb / Web sources

Press [WinKey+R], enter “%APPDATA%\Mp3tag\data\actions” into the edit line and press OK.
An Explorer window will open in the right folder.

dj 8adam-e!, did you understand what I wrote above in post #20 about the quirk when manipulating the pseudo tag-field _FILENAME with the Action “Replace”?
“Diakopes.mp3” (p->P) “DiakoPes.mP3”



hi again i’m trying to understend and your explenation is very parastatic and thanks for this but i’m not so professional in using the pc and i think that the hole problem can resolved with less technical matters and changes (i think) do you know if when i put the song in the mp3 tag it shows the .mp3 extension? there is no way to not show it …so i don’t have to do all the above?


Let us try another way of analyzing and verifying your situation.

Create a test folder.
Copy one dummy test mp3 file into this test folder.

Open Mp3tag.
Get only this one mp3 test file into list view.
Select only this one file.
Press [F2].
Enter this string into the listview’s edit field: "Test"
So you did you named this file to "Test.mp3"
You see that the manipulation of the filename is visually restricted as well as technically restricted.
Beside the manipulation of the root part of the filename there is no way to change the current file extension.
Now the filebasename is “Test.mp3”.
Press [F5].
Mp3tag displays this file in the listview.

Press [F2].
Enter this string into the listview’s edit field: “Test.MΠ3”.
Now the filebasename is “Test.MΠ3.mp3”.
Press [F5].
You should still be able to see this file in Mp3tag listview.
You see that it is not possible to change the fileextension.
The filename ist still valid.
Mp3tag can work with this file, assumingly many other applications too.

Now use Windows Explorer or some file utility alike and look into the folder where this test file resides.
Explorer must set to display the complete filename, that means filerootname and fileextension must be shown in Details view.
Rename this file from “Test.MΠ3.mp3” to “Test.MΠ3”.
You will receive a warning message that this file will be no longer of use after the renaming.
Nevertheless accept the change.

Switch to Mp3tag.
Press [F5].
The list view will be refreshed to a completely empty view.
You see that Mp3tag cannot work with the fileextension “.MΠ3”.
Use Windows Explorer to rename the corrupt filebasename from “Test.MΠ3” to “Test.mp3”-

Switch to Mp3tag.
Press [F5].
Mp3tag displays this file “Test.mp3” in the listview.

Select the test file.
Invoke the action dialog “Replace”.
Fill in the edit fields with …
Original: p (latin letter p lowercase)
Replace with: π (greek letter pi lowercase)
Leave the checkboxes empty.
Execute the action.

What did you have expected?
Actually you see in the listview the changed filename “Test.mπ3”.

Press [F5].
The list view will be refreshed to a completely empty view.
You see that Mp3tag cannot work with the fileextension “.mπ3”.
The same fact is valid for the uppercased fileextension “.MΠ3”.

As I have it explained in my above post #20, Mp3tag’s “Replace” action has a quirk when it comes to replace characters in the pseudo tag-field _FILENAME.
Action “Replace” does not respect, that the content of the psuedo tag-field _FILENAME is of format “Filerootname.Fileextension”.

Switch to Windows Explorer.
Rename the test file from “Test.mπ3” to “Test.mp3”.

Switch to Mp3tag.
Press [F5].
Mp3tag displays this file “Test.mp3” in the listview.

Do not use the Action “Replace” in conjunction with the pseudo tag-field _FILENAME to change letters, which are letters of the fileextension too.
Especially do not change any standardized fileextension like “.mp3” to any nation or language related special characters. Although doing so makes the file unusable for all the applications, which rely on the worldwide standard filename extension.

There are other ways around in Mp3tag to reach the goal of changing letters in the filerootname without corrupting the fileextension.

Yes, the answer is: Don’t do it!



Let’s just give him a solution for the problem.

A) with only one action:

Action type: Format value
Formatstring: $replace(%_filename%,M,Ϻ,P,Π,…)

B) With several actions like the original:

Action #1:
Action type: Format value
Formatstring: %_filename%

Action #2:
Action type: Replace
Original: M
Replace with: Ϻ

Action #3:
Action type: Replace
Original: P
Replace with: Π

all your replacements

Last Action:
Action type: Format value
Formatstring: %tempfilename%


In the new development version _FILENAME doesn’t include the extension anymore, so your replace action should work without changing .mp3 to .MΠ3

Try it here