# what's this suffix:  .sitx ?

**URL:** <https://boards.straightdope.com/t/whats-this-suffix-sitx/447544>\
**Category:** Factual Questions\
**Created:** [May 1, 2008, 1:06am UTC](https://boards.straightdope.com/t/whats-this-suffix-sitx/447544 "2008-05-01T01:06:24Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Northern\_Piper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/northern_piper/32/5304_2.png) [@Northern\_Piper](https://boards.straightdope.com/u/Northern_Piper)\
**Post date:** [May 1, 2008, 1:06am UTC](https://boards.straightdope.com/t/whats-this-suffix-sitx/447544/1 "2008-05-01T01:06:24Z")

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I’ve got a file on my desktop: Windows Media.sitx. I’ve got no idea where it came from, or what application it’s for.

Anyone know what the .sitx suffix if for?

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**Author:** ![Scarlett67](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/scarlett67/32/7387_2.png) [@Scarlett67](https://boards.straightdope.com/u/Scarlett67)\
**Post date:** [May 1, 2008, 1:09am UTC](https://boards.straightdope.com/t/whats-this-suffix-sitx/447544/2 "2008-05-01T01:09:28Z")

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Stuffit, which is a compression program like WinZip. I’m guessing that your mystery file is either an update installer or a compressed media file.

(For future reference, Googling the mystery extension along with “file format” usually provides enlightenment.)

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**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\
**Post date:** [May 1, 2008, 1:10am UTC](https://boards.straightdope.com/t/whats-this-suffix-sitx/447544/3 "2008-05-01T01:10:08Z")

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According to [FILExt.com](http://filext.com/file-extension/sitx), it’s an archive file format for StuffIt, a file and disk compression utility.

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**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\
**Post date:** [May 1, 2008, 1:26am UTC](https://boards.straightdope.com/t/whats-this-suffix-sitx/447544/4 "2008-05-01T01:26:49Z")

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Stuffit is a program from the Mac world. Its file extensions .sit and .sitx (among others) are common among files and programs from versions of Mac OS previous to X. Current OS X archives are usually supplied as “disk image” files (.dmg) or package files (.pkg), but you still see the occaisional .sit file, usually on files that will work both on OS 9 or before and on OS X.