# Changing File extensions

**URL:** <https://community.mp3tag.de/t/changing-file-extensions/6103>\
**Category:** Support\
**Created:** [January 20, 2008, 11:51am UTC](https://community.mp3tag.de/t/changing-file-extensions/6103 "2008-01-20T11:51:25Z")\
**Posts on this page:** 1\
**Showing post:** 2

<div class="post-metadata">

**Author:** ![dano](https://community.mp3tag.de/user_avatar/community.mp3tag.de/dano/32/6_2.png) [@dano](https://community.mp3tag.de/u/dano)\
**Post date:** [January 20, 2008, 9:30pm UTC](https://community.mp3tag.de/t/changing-file-extensions/6103/2 "2008-01-20T21:30:58Z")

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Make a [new action](https://community.mp3tag.de/t/967/1)

_Action type:_ **Replace with regular expressions**  
_Field:_ **\_FILENAME**  
_Regular expression:_ **.m4a$**  
_Replace matches with:_ **.m4b**

[] case-sensitive comparison

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_[View the full topic](https://community.mp3tag.de/t/changing-file-extensions/6103)._