What Is an XLTX File?

A file with the XLTX file extension is an Excel Open XML Spreadsheet Template file. This format is used by Microsoft Excel as a template that can be used to build multiple XLSX files that contain the same layouts, formatting, and settings.

The XLTX format was introduced to Excel in Microsoft Office 2007 to replace the older XLT template format (which creates similar XLS files).

Much like MS Office's DOCX and PPTX formats, XLTX incorporates XML and ZIP to reduce the file size.

XLTX files are normally only used with Microsoft Excel (see how to create a template file on Microsoft's website). You can open XLTX files in Excel versions older than 2007 if you install the free Microsoft Office Compatibility Pack.

The following free software can open the XLTX format as well, they just can't save the file back to .XLTX (it has to to be saved as something else like XLSX or XLT): OpenOffice Calc, LibreOffice Calc, and SoftMaker FreeOffice PlanMaker.

You can also open the file with a file decompression tool since XLTX files are actually archives. However, it's hardly a useful way to view the file's contents since it doesn't display the document like it would when opened in Excel or the other spreadsheet programs I mentioned. If you do want to go this route, for whatever reason, 7-Zip and PeaZip are two file decompression tools that could be used to open the XLTX file as an archive.

Note: If you find that an application on your PC does try to open the XLTX file but it's the wrong application or if you would rather have another installed program open XLTX files, see our How to Change the Default Program for a Specific File Extension guide for making that change in Windows.

The quickest way to convert an XLTX file to XLSX or XLS is to use one of the XLTX viewers/editors from above, like Microsoft Excel, which supports converting to both formats. The other applications listed above may only support one or the other.

Another easy way to convert an XLTX file is to use FileZigZag. It's an online file converter that can save an XLTX file to XLS, CSV, ODS, OTS, PDF, TXT, and several other formats.

Tip: If you convert the XLTX file to a more popular spreadsheet format like XLSX or CSV, you can then open the file in something other than Microsoft Excel. Some alternative free spreadsheet programs include Kingsoft Spreadsheets, Gnumeric, and Spread32.

If your file won't open or convert using the suggestions from above, then there's a really good chance that your file doesn't actually end with the .XLTX file extension. If that's the case, then you need to research that file extension to see which programs support it.

For example, XTL files appear to be related in some way to XLTX files because their file extension closely resembles that of the spreadsheet file format. However, XTL files are actually Vietcong Data files that are used by the Vietcong video game.

LTX is a similar one where the file extension looks a lot like XLTX but its format is not related in any way. LTX files might be S.T.A.L.K.E.R. Properties files or LaTeX Document files.

If it's not clear already, the whole reason you should be fully aware of the file extension is to make sure that you're using the appropriate program to open it. If you're not dealing with an XLTX file, then research the true file extension that your file has so that you can find out which programs are able to open or convert it.