# ACTIONS that mimics a WYSIWYG to Change File Extension or File Name and Extension (2022-2023)

**URL:** https://community.mp3tag.de/t/actions-that-mimics-a-wysiwyg-to-change-file-extension-or-file-name-and-extension-2022-2023/60139
**Category:** General Discussion
**Created:** [February 20, 2023, 10:00pm UTC](https://community.mp3tag.de/t/actions-that-mimics-a-wysiwyg-to-change-file-extension-or-file-name-and-extension-2022-2023/60139 "2023-02-20T22:00:48Z")
**Posts on this page:** 1
**Showing post:** 10

<div class="post-metadata">

### Author: ![LyricsLover](https://community.mp3tag.de/letter_avatar_proxy/v4/letter/l/c6cbf5/32.png) [@LyricsLover](https://community.mp3tag.de/u/LyricsLover)
#### Post date: [February 22, 2023, 7:46am UTC](https://community.mp3tag.de/t/actions-that-mimics-a-wysiwyg-to-change-file-extension-or-file-name-and-extension-2022-2023/60139/10 "2023-02-22T07:46:31Z")

</div>

> [@wneclass2018](#):
>
> cuts texts if the filename has multiple periods

Thanks for letting me know the problem with multiple dots in filenames.  
I would solve it this way:

To change only the listed extensions of selected filenames to lowercase:  
**Action "Replace with regular expression"**  
**Field:** \_FILENAME  
**Regular expression:** `^(.*)(\.(mp3|m4a|flac|mp4|aac))$`  
**Replace matches with:** `$1$lower($2)`  
_(All not listed extensions will be ignored - you can adjust the list as you like)_

To change ALL extensions in the selected files to lowercase:  
**Field:** \_FILENAME  
**Regular expression:** `^(.*)(\.(.*))$`  
**Replace matches with:** `$1$lower($2)`

You could also replace the existing extension for all selected files to a fixed new extension  
like `.aBC` with  
**Replace matches with:** `$1.aBC`

To change only the filename in all selected files to lowercase, but let the extension untouched:  
**Field:** \_FILENAME  
**Regular expression:** `^(.*)(\.(.*))$`  
**Replace matches with:** `$lower($1)$2`

To change the entire filename - including the extension - for all selected files to lowercase:  
**Field:** \_FILENAME  
**Regular expression:** `(.*)`  
**Replace matches with:** `$lower($1)`

If I would like to rename files individually per track as you suggest with your MTA's, I would use a specialized [File Rename software](https://en.wikipedia.org/wiki/Batch_renaming#List_of_software) with all the whistle and bells.

---

_[View the full topic](https://community.mp3tag.de/t/actions-that-mimics-a-wysiwyg-to-change-file-extension-or-file-name-and-extension-2022-2023/60139)._