How to Convert XLS to XLSX for Free (Easy & Fast)

October 27, 2023 3.2K views

Converting XLS to XLSX is a common need for users who want to improve file compatibility and access to modern Excel features.

However, finding a straightforward and free method to perform this conversion can be challenging. This article will provide you with useful information on how to convert XLS to XLSX for free.

What Are the Differences Between XLS and XLSX Format

XLS and XLSX are two prevalent Excel file formats, each with its unique characteristics:



Key Difference

Size Reduction when Converting to the Other Format

System & Excel Version Requirements


- Older Excel format (Excel 97-2003 Workbook)

- Uses standard binary format

Yes (when converting to XLSX)

Can be opened on a wide range of systems and Excel versions, including older ones like Excel 2003.


- Modern Excel format (Excel Open XML Workbook)

- Employs XML-based structure, offering enhanced features, improved data recovery, and smaller file sizes

Yes (when converting to XLS)

Requires a relatively recent version of Excel (Excel 2007 or newer). Also compatible with many alternative office suites and online tools.

Why You Should Convert XLS to XLSX Format

Converting XLS to XLSX offers several compelling advantages:

  • Modern Compatibility: XLSX is based on the open-standard Microsoft Office Open XML format, ensuring compatibility with a wide range of software applications and versions.

  • Enhanced Performance: For files requiring complex formulas and extensive datasets, XLSX may work more efficiently, as it utilizes modern XML-based compression methods that can improve file handling speed.

  • Expanded Data Storage: XLSX excels in handling large quantities of data, making it suitable for projects that demand extensive data storage and analysis capabilities.

  • Increased Rows and Columns: XLSX provides expanded capacity for both rows and columns, accommodating larger datasets and more extensive spreadsheets compared to XLS.

How to Change XLS to XLSX Without Opening a File

Converting an XLS file to XLSX without opening it can be done using these simple steps:

Step 1 Right-Click the File: Find the XLS file you want to convert, right-click on it to open the context menu.

Step 2 Select "Rename": From the context menu, choose the "Rename" option. Alternatively, you can click on the file once to select it and then press the F2 key to enable renaming.

Select rename

Select rename

Step 3 Change File Extension: After selecting "Rename," you'll be able to edit the file name. Change the file extension from ".XLS." to ".XLSX"



Step 4 Press Enter: Hit the Enter key to confirm the new file extension.

How to Save XLS as an XLSX File

Step 1: Open the workbook you want to convert from XLS to XLSX.

Step 2: Navigate to the "File" menu in Excel.



Step 3: Select "Save As." This action will open a dialog box.

Step 4: Click on "Browse" within the dialog box to choose where you want to save the converted workbook. Ensure you are in the correct path for saving the workbook.

Select browse

Select browse

Step 5: Under the "Save as type" dropdown menu, choose "Excel Workbook (*.xlsx)".

 Select format

Select format

Step 6: Finally, click "Save" to save the XLS file as an XLSX file in the selected location.

 Click Save

Click Save

How to Convert XLS to XLSX Using Free Online Converter


Zamzar is a free online file conversion service that supports over 1200 different conversions. You can convert files between various formats, such as video, audio, image, document, and ebook. You can also convert files from a URL or a cloud service

Step 1: Go to the Zamzar website.

Step 2: Click on the "Choose Files" button and select the file you want to convert.

Step 3: Select the xlsx format from the "To format" drop-down menu.

 Select format

Select format

Step 4: Click on the "Convert now" button.

Click covert now

Click covert now

Step 5: Click Download and the converted file will be downloaded to your computer.


Convertio is another free online file converter that can handle various types of files, including XLS and XLSX. Convertio also has a premium plan that offers more features, such as unlimited conversions, OCR, and batch processing.

Step 1: Go to the Convertio website.

Step 2: Click on the "Choose Files" button and select your XLS file.

Step 3: Select the "XLSX" format as the output

Step 4: Click on the "Convert" button.

Click Convert

Click Convert

Step 5: Afer the process click Download to download your converted file


Smallpdf is a free online tool that specializes in PDF-related tasks, such as converting, compressing, editing, and signing PDF files. You can also use it to convert XLS to XLSX. Smallpdf also has a pro plan that gives you access to more tools, such as e-signatures, password protection, and unlimited conversions.

Step 1: Go to the Smallpdf website.

Step 2: Click on the "Select file" button and select your XLS file.



Step 3: Select the "XLSX" format from the "Convert to" drop-down menu.

 set up

set up

Step 4: Click on the "Convert" button.

Select convert

Select convert

Step 5: The converted XLSX file will be opened in your browser. You can then download it to your computer by clicking on the "Download" button.

Click download

Click download

Best Free Alternative to Microsoft Excel - WPS Spreadsheet

WPS Office

WPS Office

WPS Office is a free and comprehensive office suite that includes Writer, Spreadsheet, Presentation, and PDF modules. It is compatible with Windows, macOS, Linux, Android, and iOS platforms and supports 47 file formats and 46 languages. WPS Office is a great alternative to Microsoft Excel for creating and editing spreadsheets.

Advantage of WPS Office

  • Free download and free use: WPS Office is a free and open-source office suite that includes a word processor, spreadsheet, presentation maker, and more.

  • Delicate Template Store: WPS Office provides a wide range of templates for various document types, simplifying the process of creating professional-looking documents.

  • Rich Features: It includes features for data analysis, chart creation, and formatting, similar to Microsoft Office. Plus, it supports major file formats for easy compatibility.

  • Lightweight: WPS Office is resource-efficient, making it suitable for older computers or areas with limited internet connectivity.

  • Online Collaboration: You can collaborate on documents in real-time, making it ideal for students, businesses, and collaborative projects.

  • Compatibility: It works on various operating systems and supports major file formats, ensuring seamless document sharing across platforms.

  • User-Friendly: WPS Office offers a user-friendly interface, resembling Microsoft Office, which makes it easy to learn and use.

If you are looking for a free alternative to Microsoft Excel that can meet your spreadsheet needs, you might want to give WPS Spreadsheet a try. You can download it from the official website

WPS Office- Free All-in-One Office Suite
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Algirdas Jasaitis


How do I batch convert multiple XLS files to XLSX files in Excel?

To batch convert multiple XLS files to XLSX format in Excel, you can utilize VBA code. This enables you to transform multiple files at once.

Can I convert XLS format to XLSX format automatically?

Yes, you can automate the conversion from XLS to XLSX format. Utilizing VBA code allows you to streamline this process efficiently.

Can I perform the conversion without losing any data or formatting?

Yes, converting from XLS to XLSX format can be done without losing any data or formatting. The process is designed to retain all information intact, ensuring a seamless transition.


In this guide, we've explored the seamless conversion of XLS to XLSX, emphasizing the advantages and providing easy-to-follow steps. Throughout this journey, one tool stands out: WPS Office.

With WPS Office, you gain free access to Word, Excel, and PowerPoint, along with a powerful PDF toolkit and a plethora of templates. Its rich features, light design, and online document support redefine productivity. Additionally, collaborative functions like co-editing and group sharing set it apart. Choosing WPS Office isn't just about file conversion; it's about embracing a more efficient way of working

15 years of office industry experience, tech lover and copywriter. Follow me for product reviews, comparisons, and recommendations for new apps and software.