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XLS and XLSX: All You Need to Know
 XLS and XLSX: All You Need to Know

XLS and XLSX: All You Need to Know

by Alexa Davis
Jun 19, 2024

Excel files have been essential document formats for decades, but if you're new to the game you might be confused by the different extensions: XLS vs XLSX.

In this article, we'll delve into the primary distinctions among MS Excel file formats. While many of us are proficient in Microsoft Excel, some may overlook the existence of two distinct yet interconnected file extensions.

Whether you're a novice in spreadsheet software or aiming to enhance your expertise, grasping the difference between XLS and XLSX is certainly a valuable investment of your time!


What is XLS?

Microsoft introduced the XLS extension in the late 1980s, which swiftly gained popularity as a standard for spreadsheets and databases.

This open-source format, rooted in XML, was primarily tailored for compatibility with Microsoft Excel. It facilitates the storage of data in tables, columns, and chart formats, alongside capabilities for formulas, organization, sorting, and layout adjustments.

Frequently employed for storing financial data like budget sheets, sales records, and expense trackers, the XLS format boasts features such as automatic chart generation from stored data. This functionality proves invaluable for swiftly presenting quantitative data to decision-makers.

What is XLSX?

The XLSX format is a structured electronic document extension crafted for storing and sharing data in spreadsheet form. Originally developed by Microsoft in the early 2000s, it has since emerged as one of the most prevalent formats for data exchange.

Built upon the XML-based Open Packaging Convention (OPC) specification, it organizes data in a hierarchical manner.

This approach offers several advantages over older formats, which were confined to fixed-pitch layouts. Consequently, XLSX enables more efficient storage of spreadsheet data. This leads to faster download speeds, simplified sharing of large files, and enhanced interoperability with various databases.

XLSX is also fully compatible with major worksheet applications such as Microsoft Excel, Apple Numbers, and Google Sheets.


XLS and XLSX are file formats primarily associated with Microsoft Excel, offering compatibility with different workbook software.

Here are some key similarities between the two formats:

  • Both XLS and XLSX were developed by Microsoft.
  • Both formats are designed to store spreadsheet data, including text, numerical values, formulas, and formatting information.
  • Users can perform similar manipulation tasks with either format, such as organizing data, applying functions, and configuring layout settings.
  • Both extensions support the automatic generation of charts or visualizations from stored data, aiding in the presentation of quantitative information.
  • XLS and XLSX formats are widely compatible with various applications, including Microsoft Excel, Apple Numbers, and Google Sheets.
  • Despite differences in the underlying structures, these formats both organize data in a structured manner that facilitates efficient storage and retrieval of information.

Differences between XLS and XLSX

IntroductionLate 1980sEarly 2000s
File FormatBinaryXML-based on OPC specification
File SizeTends to have larger file sizesGenerally smaller file sizes due to compression
CompatibilityMay have compatibility issues with newer software versionsBetter compatibility with the latest applications
FeaturesLimited features compared to XLSXSupports additional features like enhanced security options, improved data recovery, and larger worksheet sizes

Reasons to convert XLSX to PDF

Converting XLSX (Excel) files to PDF format can be beneficial for several reasons:

  • Universal Viewing. PDF files can be viewed on various devices and operating systems without requiring specific apps.
  • Preservation of Formatting. PDFs maintain the appearance of the original Excel document, including fonts, colors, images, and layout. This ensures that the document's visual presentation remains consistent across different devices and platforms.
  • Security. PDF files offer security options such as password protection and permissions settings, which can restrict access to sensitive information contained in the Excel document.
  • Printability. PDF format is optimized for printing, ensuring that everything is preserved on a hard copy.

How to convert XLSX to PDF online

If you are looking for a quick and reliable way to convert XLSX to PDF without the need to install software, opting for an online solution is your best bet. PDF Candy offers an efficient online tool for seamless file conversion, requiring no registration.

Here’s a step-by-step guide on how to use it:

  1. Open the Excel to PDF converter in your browser.
  2. Pick the XLSX file you want to convert and upload it to the service. Alternatively, you can add it from your Google Drive or Dropbox.
  3. The conversion process will start automatically.

With an online converter such as PDF Candy, concerns about desktop compatibility are alleviated. You won't find yourself in a situation where you need a specific version of the program to ensure successful file conversion.

Convert XLSX and XLS files to PDF online

All that’s required is a browser connected to the Internet, that’s it! Plus, all processes are done fast and securely. So don't waste time anymore and try PDF Candy now!

How to convert XLSX/XLS to PDF offline

Whether you are a teacher or a student, you are likely soon to encounter situations where you need to convert XLSX to PDF. Fortunately, with the help of PDF Candy Desktop, converting your files can be quick and easy!

Unlike an online service, this software can be installed onto your computer and used offline.

Therefore, this secure solution enables you to process files without constraints on file size. Moreover, using a desktop-based Excel to PDF converter can significantly optimize the whole process time-wise.

PDF Candy Desktop contains an extensive list of tools that support various file formats such as DOCX, XLSX, JPG, PNG, and more.

To use this program and convert XLSX to PDF follow these steps:

  1. Download PDF Candy Desktop and install it on your device.
  2. Open the program and locate the "Excel to PDF" tool.
  3. Add the desired XLSX, XLS or CVS files. Alternatively, you can drag and drop the files over the tool icon.
  4. The document should now appear in the list visible in the middle part of the working window. You can convert multiple XLSX files to PDF at once.
  5. Click "Convert" at the lower right side of the program window.

With PDF Candy Desktop you can forget about tedious processes associated with conversion and relax knowing that your files will be converted locally!

Offline XLS to PDF converter


Can I convert XLS files to XLSX and vice versa?

Yes, you can do it using Microsoft Excel or various online file conversion tools. Keep in mind that some formatting or features may be lost or altered during the process.

How do XLS and XLSX handle macros and VBA (Visual Basic for Applications) code?

XLS files may contain macros and VBA code embedded within the file, which can be executed within Microsoft Excel. XLSX files can still contain the same information, but they need to be saved as a macro-enabled workbook (.xlsm) to preserve this functionality.

How do XLS and XLSX work with complex formulas and functions?

Both extensions support a wide range of functions for complex calculations and data analysis. However, XLSX offers improved performance and stability for handling formulas.

XLS vs XLSX - conclusion

The XLS versus XLSX comparison becomes clearer with the insights shared in this article. It's crucial to understand that XLS files, being the older format, are primarily compatible with legacy software. Whereas XLSX files leverage modern XML coding for better data optimization and broader compatibility with contemporary solutions.

When converting these varied formats into a unified PDF file, it's vital to conduct thorough research on the program you intend to use.

Try other tools

  • Compress the resulting PDF for easier sharing.
  • Divide the document using 4 different modes.
  • Use an online PDF editor to accurately edit converted Excel spreadsheets.
  • Set a strong password for your PDF file.
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