File Extension TG File Format Gzip Compressed Tar Archive TG stands for Gzip Compressed Tar Archive. This was last updated in March 2012 By Margaret Rouse Browse File Extensions Alphabetically: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # Ask a Question. Find an Answer. Ask your peers a question about this file extension. Ask a Question Open/convert TG4 files Oracle App Server webcache and mod_gzip Tech Quiz of the Day from WhatIs.com: What do you know about gzip?