XLS to XLSX - Convert document online

(DOC, DOCX, RTF, TXT, ODT, XLS, XLSX, CSV, ODS, PPT, PPTX, ODP, HTML, XPS, etc.)
Conversion Results:
# Output File Source File Action

How to convert XLS to XLSX:

1. Click the "Choose Files" button to select multiple files on your computer or click the "URL" button to choose an online file from URL, Google Drive or Dropbox.

2. Choose a target document format. The target document format can be PDF, DOC, DOCX, XLS, XLSX, PPT, PPTX, HTML, TXT, CSV, RTF, ODT, ODS, ODP, XPS or OXPS. A target format can only be converted from certain document formats. For example: It can convert DOC to DOCX, but it can't convert DOC to XLSX. When choosing a target format, it will list what source formats can be converted to the target format.

3. Click the "Convert Now!" button to start batch conversion. The output files will be listed in the "Conversion Results" section. Click icon to show file QR code or save file to cloud storage services such as Google Drive or Dropbox.

XLS vs XLSX:
Name XLS XLSX
Full name Microsoft Excel Binary File Format Office Open XML Document
File extension .xls .xlsx, .xlsm
MIME application/vnd.ms-excel application/vnd.-openxmlformats-officedocument.-spreadsheetml.-sheet
Developed by Microsoft Microsoft
Type of format Spreadsheet Spreadsheet
Introduction Microsoft Excel up until 2007 version used a proprietary binary file format called Excel Binary File Format (.XLS) as its primary format. Excel 2007 uses Office Open XML as its primary file format, an XML-based format that followed after a previous XML-based format called "XML Spreadsheet". The Office Open XML file formats are a set of file formats that can be used to represent electronic office documents. There are formats for word processing documents, spreadsheets and presentations as well as specific formats for material such as mathematical formulae, graphics, bibliographies etc.
Technical details OpenOffice.org has created documentation of the Excel format. Since then Microsoft made the Excel binary format specification available to freely download. Office Open XML documents are stored in Open Packaging Convention (OPC) packages, which are ZIP files containing XML and other data files, along with a specification of the relationships between them. Depending on the type of the document, the packages have different internal directory structures and names.
Associated programs Microsoft Office, LibreOffice, Kingsoft Office, Google Docs. Microsoft Office, LibreOffice, Kingsoft Office, Google Docs.
Sample file sample.xls sample.xlsx
Wikipedia XLS on Wikipedia XLSX on Wikipedia