Convert XLS to XLSX for Free

by Hung Nguyen

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The manual method to convert XLS to XLSX entails opening the file from Microsoft Excel and saving it as another format. Conventional file formats that you could save to include Excel Template (.xltx), .htm, and of course, the standard Excel Workbook (.xlsx). However, if you do not have access to the Office software, or your current machine cannot handle to open larger XLS files, you can use Smallpdf’s Excel to PDF converter to convert your documents, for free.

How to convert XLS to XLSX online for free

  1. First, save the XLS to PDF.

  2. Download the first file, and then click ‘PDF to Excel’ on the footer.

  3. Drag the downloaded file into the second, darker green toolbox.

  4. It will now convert to XLSX. Download this file.


How to convert .xls to .xlsx spreadsheets

As you’ve guessed, Smallpdf first takes the XLS file to save it as a PDF, before converting it to an XLSX file. As a matter of fact, any Excel-saved file saved as a PDF will be saved as an XLSX - the standard output type for our converter. Whether you decide to use your spreadsheet application to convert your digital files manually, or our online tool is entirely up to your preference. Smallpdf uses the same conversion method from Microsoft Office itself; thus, the output should not be of any difference.

Should I use XLS or XLSX?


XLS is the older Excel spreadsheet that was used prior to the 2007 version release (XLSX) and is a binary interchange file format. On the other hand. The XLSX format, released alongside Excel 2007 offers much higher compatibility with different operating systems, and many of the widely used functions that we utilize every day to date: graphics, calculations, pivot tables, and Visual Basic.

XSLX, as opposed to XSL (a binary file format), is an XML file format - where data is stored in a text file that uses XML to define various parameters. I suppose your needs also depends on whether you can open XML documents, compatibility with your current device, or even requirements made by third-parties - if you are sharing files in a work environment.

May I convert XLS to XLSX free of charge?


The two aforementioned tools to use in combination to get a file from XLS to XLSX are both free for occasional use. Better yet, so are the 16 other tools on our website to convert XML formats from one to another. Data sources, formatting, colors, and images will be retained, as close to the original versions of Excel, as possible. This statement is also applicable to other file types within the Microsoft Office family.

Once you have run out of the free usage, a half-month trial is available for free as well, for you to take advantage of. Check out our ‘Pro’ page for more information on the reaped benefits of subscribers, such as batch conversion, faster upload speed, and offline processing.

Hung Nguyen
Hung Nguyen
Content Marketing Manager @Smallpdf