SITX File Extension
StuffIt X Archive
- File Type sitx
- Developer Smith Micro
- Popularity
- Application StuffIt
- Category Compressed Files
- Format Binary
What is a SITX file?
StuffIt X Archive, identified by the SITX extension, is a Compressed Files type and includes 820 files.
With the creation of the StuffIt X Archive (SITX), Smith Micro introduced file format along with 7 programs built for their use.
SITX files are supported by Windows and Mac OS. You can extract a SITX file using one of 6 programs, for example StuffIt, The Unarchiver and StuffIt Deluxe.
File Signature
HEX code: 53 74 75 66 66 49 74 21. ASCII code: StuffIt!.
Programs that support SITX files
How to open a SITX file?
The most common reason why a SITX file cannot be opened is the absence of required software. To fix this, select a compatible program from the list. Then visit the official developer website via the provided link, download the program, and install it on your system.
The most popular programs for working with SITX files are StuffIt, The Unarchiver and StuffIt Deluxe. To get the latest version of StuffIt, open the Smith Micro website where a universal installer for all operating systems is available.
Once setup is done, your operating system should assign StuffIt as the default app for SITX files.
Make StuffIt the default SITX viewer
Changing the default program in Windows
- Start by right-clicking on your SITX file and selecting the "Open With" option. From there, click "Choose another app" to continue;
- Inside the popup window, scroll through the list of applications and specifically choose StuffIt as the application to associate with your SITX file;
- Check the "Always use this app" checkbox and click "OK".
Change the default app to open files on Mac
- Right click or use Control + Left Click on the desired SITX file to access a dropdown menu of actions;
- Select "Open in application" and click "Other";
- Scroll down to the bottom of the window, where you will find the "Enable" menu. Default, "Recommended Programs" will be selected;
- In this menu, choose "All Programs" and navigate to StuffIt. Check the box next to "Always open in app" to make it the default program.
Convert to and from SITX
If a SITX file is difficult to handle, you might try converting it to formats such as ZIP, SI or similar, which may be easier to work with.
Please note that after converting a SITX file, some functionality may differ from the original. However, in many cases, it can be converted back to its original format.
Convert SITX to other file formats
Finding answers to SITX file problems
If you encounter issues with SITX files, don’t worry—most can be fixed with minor software adjustments. Refer to the troubleshooting tips below.
What are the signs that my SITX file is damaged?
Corrupted SITX compressed files may have one or more of the following symptoms:
- Poor performance when editing a file in StuffIt;
- Opening or processing the file in StuffIt or other programs causes instability or crashes in the program;
- The file shows errors when trying to open it or does not open completely;
- Unexpected expansion of the total size of the SITX file;
- Working with the file triggers the display of error messages;
Why does StuffIt quit or crash unexpectedly?
StuffIt crashes can be attributed to outdated software. Make sure you have installed the latest updates for Smith Micro products.
A computer restart is often the key to solving numerous common problems. That’s why, it is recommended to restart the computer before making any changes to the software settings.
What methods can be used to repair a damaged SITX file?
Use a recovery program to open the damaged SITX file and navigate to the "Repair" menu item. Wait for the recovery process to finish, as it will automatically repair damaged compressed files.
How to edit a SITX file?
To edit SITX files, you need to install specialized software that allows you not only to open but also to modify compressed files. Online SITX editors usually provide fewer features than software created specifically for StuffIt X Archive.
List of Top SITX editors 2026
Following these criteria, we have put together a list of recommended SITX editors.
| SITX Editor Software | Developer | Platforms | Overall Rating |
|---|---|---|---|
| StuffIt | Smith Micro | Mac OS, Windows | 4.7 out of 5 (39 reviews) |
| StuffIt Deluxe | Smith Micro | Mac OS, Windows | 4.4 out of 5 (40 reviews) |