Software & Apps File Types What Is an XLTX File? How to open, edit, and convert XLTX files By Tim Fisher General Manager, VP, Lifewire.com Tim Fisher has 30+ years' professional technology support experience. He writes troubleshooting content and is the General Manager of Lifewire. our editorial process Facebook Twitter LinkedIn Tim Fisher Updated February 27, 2020 File Types Design Cryptocurrency MS Office Windows Linux Google Drive Apps File Types Backup & Utilities View More Tweet Share Email A file with the XLTX file extension is an Excel Open XML Spreadsheet Template file. This is a Microsoft Excel template format used to build multiple XLSX files that contain the same layouts, formatting, and settings. The XLTX format replaced the older XLT template format from Office 2007 and earlier (which creates similar XLS files). It incorporates XML and ZIP to reduce the file size. Instructions in this article apply to Excel 2019, 2016, 2013, 2010, Excel for Mac, and Excel 365/Online. How to Open an XLTX File XLTX files are normally only used with Microsoft Excel. 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 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 we 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. 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, you can change the default program. How to Convert an XLTX File 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. 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 WPS Office, Gnumeric, and Spread32. Open your browser and go to FileZigZag. Either select Browse for Files or drag and drop the XLTX file you wish to convert. When the Open dialog comes up, browse to the file(s) you wish to convert. Select it, then select Open. Under Files to convert, you should see the file(s) you've added. Select the format you wish to convert to under Target Format. Select Start Converting. Once the file is converted, select Download to obtain the new file. Still Can't Open Your File? If your file won't open or convert using the suggestions from above, then there's a high probability that your file doesn't 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 can open or convert it.