2 Easiest Ways to Convert XLSX to XLS for Free (Guide for Beginners)

October 27, 2023 1.3K views

Converting XLSX to XLS can be necessary for compatibility with older software versions or specific requirements.

However, many users don't know how to do this quickly and easily. This article will provide you with two easy and free methods to convert XLSX to XLS without losing data or formatting.

What Are the Differences Between XLSX and XLS Format

XLS and XLSX are two file formats used in Microsoft Excel, and they serve similar purposes for storing spreadsheet data, but there are some significant differences between them:




File Format

Older binary format

XML-based format

File Size




Compatible with older Excel versions

Requires Excel 2007 or later

Data Structure


XML-based compression


Limited support for advanced features in newer Excel versions

Better support for advanced features

File Extension



Compatibility Mode

Needed in newer Excel versions for XLS files

Not needed for XLSX files

2 Easiest Ways to Convert XLSX to XLS (In Easy Steps)

Method 1: Save XLSX as an XLS file

Step 1: Open Excel:

Launch Microsoft Excel and open the XLSX file you want to convert.

Step 2: Click on "File":

Access the file menu by clicking on the "File" tab in the top-left corner.

Click file

Click file

Step 3: Select "Save As":

Choose "Save As" from the dropdown menu to open the saving options.

Click Save as

Click Save as

Step 4: Choose File Format:

Select the location and then choose "Excel 97-2003 Workbook (*.xls)" from the "Save as type" dropdown menu.

Choose format

Choose format

Step 5: Click "Save":

Confirm the save operation by clicking "Save". The XLSX file will now be saved in XLS format.

Click Save

Click Save

Method 2: Using Free Online Converter


Step 1: Visit Zamzar:

Open your web browser and go to the Zamzar website by visiting .

Step 2: Upload Your XLSX File:

Click on the "Choose Files" button to upload your XLSX file from your computer.

Choose file

Choose file

Step 3: Select Output Format (XLSX):

In the "Convert to" dropdown menu, choose "XLS" as the desired output format.

Choose forrmat

Choose forrmat

Step 4: Click Convert Now to start the process




Step 1: Visit Convertio:

Go to the Convertio website by visiting .

Step 2: Upload Your XLSX File:

Click the "Choose Files" button to upload your XLSX file from your computer.

Upload file

Upload file

Step 3: Select Output Format (XLSX):

Choose "XLS" as the output format by clicking on the dropdown menu.

Choose XLS

Choose XLS

Step 4: Convert:

Click the "Convert" button to initiate the conversion process.

Click Convert

Click Convert


Step 1: Visit Smallpdf:

Access the Smallpdf website by going to .

Step 2: Upload Your XLSX File:

Click on the "Select Files" button to upload your XLS file from your device.

Select file

Select file

Step 3: Start Conversion:
Select Output formart then  Click the "Convert" button to begin the conversion process.

Click convert

Click convert

Step 4: Download the Converted File:

Once the conversion is complete, you'll be able to download your XLSX file directly from the website.

How to Fix “Excel Cannot Open the File Because the Extension Is Not Valid”

not valid

not valid


Check the file extension. Ensure that it is indeed an Excel file with either the .xls or .xlsx extension.Make sure the file hasn't been corrupted. Try opening it on a different device or ask for a fresh copy if possible.

Step 1: Open Excel in Safe Mode

Launch Excel in Safe Mode to eliminate potential conflicts with add-ins or extensions.

For Windows: Press Win + R, type excel /safe, and hit Enter.

Step 2: Use "Open and Repair" Feature

In Excel, go to File > Open.

Click Open

Click Open

Browse and select the problematic file.

Step 3 Click the dropdown arrow next to the "Open" button and choose "Open and Repair".

Open and Repair

Open and Repair

Step 4 A dialog box pop-up, click on repair

Click Repair

Click Repair

Reminder: Remember to always keep backups of your important files and be cautious when downloading or receiving files from external sources. Following these steps should help you resolve the issue and regain access to your Excel file.

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Why is my Excel saving as XLSX?

In Microsoft Excel, workbooks are automatically saved in the .xlsx format. You have the option to change the default file format to any other supported format within Excel.

Why would I need to convert XLSX to XLS?

Converting from XLSX to XLS might be necessary for compatibility with older software versions or specific requirements. This ensures that your files can be easily accessed and utilized across various software environments.


This comprehensive guide covers various aspects of Excel file management, including converting between XLSX and XLS formats, troubleshooting common extension issues, and introducing WPS Office as a powerful alternative to Microsoft Excel.

The guide emphasizes the strengths of WPS Office, highlighting features such as free access to Word, Excel, PowerPoint, a rich template store, and a user-friendly interface. With this knowledge, users can confidently navigate Excel files, with a spotlight on the capabilities of WPS Office as a valuable tool in the office suite landscape.

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