Popular formats


Opening xls files

Have a problem opening a .xls file? We collect information about file formats and can explain what xls files are. Additionally we recommend software suitable for opening or converting such files.

What is the .XLS file type?

A file having the XLS file extension represents a binary Microsoft Excel worksheet file. An XLS file is used for storing information in a grid of vertical columns and horizontal rows. That tabular scheme enables creating charts and graphs and performing various calculations and statistical analysis.

The XLS file format was used by default for saving documents in pre-2007 Excel editions. Then it was replaced by an XML-based format with the .xlsx extension. Despite adoption of the new format, .xls documents are still supported and readable by all Excel products, including 2007 or later.

The inner content of a .xls file is organized in series of streams and substreams with their proper Beginning of File and End of File records. The primary stream in XLS is the Workbook stream which in turn contains the Globals substream and sheet substreams.

Apart from commercial Excel, there are some other third-party apps designed for opening .xls workbooks or converting them into other file formats. They can also perform auxiliary tasks like merging data from multiple XLS documents or copying calculation formulas.

Software to open or convert XLS files

You can open xls files with the following programs: