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XLS vs XLSX: Differences & 3 Ways to Convert Them

XLS and XLSX are both spreadsheet formats developed by Microsoft

4 min. read

Updated onOctober 7, 2024

updated onOctober 7, 2024

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Whenworking on Microsoft Excelfiles, you might have come across two formats, i.e., XLS and XLSX and you might have wondered what are the difference between the two.

In this guide, we will share a guide that explains the differences between XLS vs XLSX and all the different ways to convert them. Let us check out the guide.

XLS vs. XLSX: What are they?

1. What is XLS?

The XLS format is a file format developed by Microsoft that is used by Microsoft spreadsheet programs known as Excel. It is a default file format for saving spreadsheet files.

When you launch the MS Excel program, you will be shown a blank spreadsheet that can be added with multiple columns, rows, calculations, and other data.

The XLS format is an old Excel format that uses proprietary binary, more formally known as BIFF or Binary Interchange FileFormat.

It was first introduced in 1987 when the Microsoft Excel program was released. The XLS file format was later replaced by the XLSX format.

2. What is XLSX?

On the other hand, the XLSX format is a Microsoft spreadsheet designed to be used not only on Windows, but across all platforms such as Android, iOS, and macOS.

When dealing with an XLSX file, you instantly understand that the file may contain calculation, pivot tables, graphing tools, and programming tools such as Visual Basic for apps.

After Microsoft update the Office in 2007, the letter X was added to many of its extensions, such as DOCX, PPTX, and XLSX.

The XLSX file format is more compatible with diverse software outside of Windows and contains Excel data not provided by XLS, including advanced formulas, charts, media, and formats. So if you run into theexcel error extension not valid, it’s probably because it is of the XLS format.

XLS vs XLSX: Differences

How do I convert XLS to XLSX and XLSX to XLS?

1. Simply rename the files

This is one of the easiest ways to convert XLS format to XLSX format or vice versa. This doesn’t require the usage of any software and lets you convert between XLS vs XLSX.

2. Convert using MS Excel

You can also use Microsoft Excel software to change the extension of the XLS file to XLSX or XLSX file to XLS. This will help you to get the file in the desired format to be able to run in the supported version of MS Excel.

3. Use online converters

You can always rely on the internet for some free tool that can help you to convert XLS to XLSX and vice versa. You can use one of the many websites out there likeCloudConvertthat will help you convert the files.

All you need to do is upload the XLS or XLSX file and select the output format and download it. That’s it. It is as easy as that. If you want to learn more about Excel, we have a great guide how to copy data fromExcel to Word, so don’t miss it.

Feel free to let us know in the comments below if this guide helped you understand the difference between XLS vs XLSX.

XLS vs XLSX: Differences & 3 Ways to Convert Them#

XLS vs. XLSX: What are they?#

1. What is XLS?#

2. What is XLSX?#

XLS vs XLSX: Differences#

How do I convert XLS to XLSX and XLSX to XLS?#

1. Simply rename the files#

2. Convert using MS Excel#

3. Use online converters#