Translation Memory eXchange (TMX) is an XML based standard for importing and exporting translation memories created by computer-aided translation and localization tools.

Since 1998 the standard was originally developed within the Container/Content Allowing Reuse (OSCAR) committee at the Localization Industry Standards Association (LISA).

After the insolvency of LISA in 2011, the standard has been put under Creative Commons license and is freely available in its currently version 1.4b at the GALA homepage.

The TXM is a standardised format for representation of translation memory data. It is widely used in the translation and localization industry to exchange translation memory content between various translation data or translation-related tools.

The TMX specification is defined in two parts:

• "A specification of the format of the container (the higher-level elements that provide information about the file as a whole and about entries). In TMX, an entry consisting of aligned segments of text in two or more languages is called a Translation Unit (the <tu> element).
• A specification of a low-level meta-markup format for the content of a segment of translation-memory text. In TMX, an individual <segment> of translation-memory text in a particular language is denoted by a seg element." See the TMX 1.4b Specification for more details.