.XLSX File Extension

Microsoft Office Excel (2007+) Spreadsheet

Data File
XLSX is the default format used by Microsoft Excel, versions 2007 and above. Microsoft Excel is compatible with multiple operating systems and it's currently one of the top applications for creating and editing spreadsheets.

The XLSX format stores data in worksheets. Each worksheet has a grid of cells arranged in columns and rows. Cells can contain text and numbers of various fonts, colors and sizes. XLSX files may also include charts, pivot tables, graphs and mathematical functions. Microsoft Excel also features the Visual Basic macro programming language for applications.

XLSX files are based on the Open XML format which stores all content in a zipped archive. The archive contains XML, RELS and media files (if applicable) stored in three separate folders named “docProps”, “xl” and "_rels". Files with the RELS extension dictate how the parts of the document connect to form a single file. The archive also includes a [Content_Types].xml file which describes the spreadsheet and separate XML files for each worksheet. This archived approach makes file content more accessible. For example images and text are stored individually within the archive.

How to open XLSX files

The contents of an XLSX file can be extracted individually by opening it with a data compression application (i.e. WinZip or WinRAR). The XML files of an XLSX document can be opened with any basic text editor and any web browser.

XLSX files can be opened with a large number of applications including online word processors.

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Comments (5)
showing 1-5
Flat Rockit
2008-12-08 12:45:12
What a nasty little suprise. I buy a new PC with Vista and get Office 2007. Now when I send a friend a spread sheet with basic club info.; he can not open it.

Vista windows explorer did not show me the .xlsx extnsion. But good old CMD did. Grrrr. Grrr.Would be nice to have an option to save stuff with plain old .xls for my down rev friends who do not really need all the fancy do dah "improvements". Hey Mr. Bill; there are a bunch of former friends of Bill out here who would pay for a version that offered retro as an option.

With PCs having enough power to re-calc the interest on the national debt in a second; shouldn't be a big deal. It would help us out not to have to keep buying upgrades during the recession.
Jay /
2008-12-08 16:50:03

Excel does have an option to export to retro .XLS format. When you go to save your spreadsheet, you'll see a drop-down list titled "Save as type", click this box and you should see "Excel 97-2003 workbook" - this will save your files in the old .xls format.
Ian Fischer
2009-01-06 06:55:03
I have a 32 gig flash drive with an Excel (Office 2007) file on it containing all my passwords and private information.

After installing a new HDD and reinstalling MS Office 2007, I now find that I cannot open the Excel file and keep getting the message about the "xlsx format etc".

I have tried everything I know to open it but nothing works! Is there any way I can get this wretched file to open or have I lost everything?

Thing is it was all created on the 2007 Excel and nothing has changed except re-installation. Thanks!
Jay /
2009-01-06 09:43:20
Hi Ian,

What is the full text of the error?
Mike Sawyer
2009-01-27 05:12:01
I am having similar problems with xlsx files on Vista with Office 2007. When I save them I cannot reopen them - it says they are either corrupt or not able to be opened by Excel 2007, also happens if I try to save them as 2003 format xls, wont let me reopen them