What is the standard file extension for spreadsheet files?

The standard file extension for spreadsheet files is typically .xlsx, which is used by Microsoft Excel and represents spreadsheet files created in versions after Excel 2007. This file format is part of the Office Open XML standard, allowing for greater compatibility across various software and platforms.

The .xls extension, while also a spreadsheet file format associated with Microsoft Excel, was primarily used in earlier versions of Excel (pre-2007). Although .xls files are still commonly used and recognized, .xlsx has become the predominant format due to its advantages in terms of file size, features, and compatibility with newer software.

The .doc extension is a format associated with Microsoft Word documents, while the .csv extension represents Comma-Separated Values files, which are primarily used for importing and exporting data in a simple text format, rather than functioning as a full-featured spreadsheet file. Therefore, .xlsx is the most accurate representation of the standard file extension for modern spreadsheet files.