Convert XLS to XLSX

Choose file to convert

You have the option to convert your xls file to xlsx, as well as a variety of other formats, using our free online converter.

How to convert xls to xlsx?

How to convert xlsx to xls?

Step 1

Upload xls-file

You can select xls file you want to convert from your computer, Google Drive, Dropbox or simply drag and drop it onto the page.

Step 2

Select «to xlsx»

Choose xlsx or any of the other 200+ supported formats you'd like to convert to.

Step 3

Download your xlsx file

Please wait for the conversion to complete, then click on the download button to obtain your converted file in the xlsx format.

The security of your files is our priority

Understanding the importance of the security of our users' data, we have implemented a number of measures to ensure reliable file conversion without the risk of information leakage or privacy violations.

Data encryption

All information uploaded to our platform is SSL encrypted, ensuring privacy during transmission.

Safe storage

After the conversion is completed, the files are stored on secure servers for 24 hours and are automatically destroyed, excluding access by third parties.

Harmless scripts

Our file conversion tools are regularly tested for malicious code or vulnerabilities to eliminate the risk of a potential cyber attack.

Best tool to convert xls to xlsx

xls to xlsx Fast and easy

Simply drag and drop your xls files onto the webpage, and you'll be able to convert them to xlsx or over 250 different file formats, all without having to register, provide an email address, or include a watermark.

Secure xls to xlsx Conversion

As soon as you upload your xls files, we instantly delete them. Converted files are then deleted after 24 hours. Furthermore, we ensure that all file transfers are secure through advanced SSL encryption.

No Software Installation Required

You don't have to go through the hassle of installing any software. We handle all xls to xlsx conversions in the cloud, which means that none of your computer's resources will be used in the process.

Microsoft Excel Binary File Format

Extension	.xls
Category	🔵 documents
Programs	🔵 Microsoft Office 🔵 LibreOffice 🔵 Kingsoft Office 🔵 Google Docs
Main program	🔵 Microsoft Office
Description	🔵 The .xls format is the default file format for spreadsheets created in Microsoft Excel, particularly in versions before Excel 2007. This binary file format can store data in cells organized in rows and columns, and it supports formulas, charts, graphs, and various formatting features to manipulate and visualize data. The .xls format was commonly used in business, finance, and any field requiring data analysis and presentation, but has since been largely replaced by the more advanced .xlsx format.
Technical details	🔵 The `.xls` format, primarily used for Microsoft Excel versions before 2007, stores spreadsheet elements such as worksheets, formulas, and macros. Being a proprietary binary format created by Microsoft, its undocumented internal structure has made compatibility with third-party software quite challenging. This format consists of binary records that contain data, formatting, and embedded objects, allowing for multiple worksheets, various functions, and inter-sheet referencing. `.xls` files can also include Visual Basic for Applications (VBA) macros, which enable automation and complex calculations. While supported in applications like OpenOffice Calc, there are options available to convert between `.xls` and other formats such as `.xlsx`. Despite security concerns related to macros, `.xls` is still commonly used due to its compatibility with older Excel versions and legacy systems. However, the newer `.xlsx` format, introduced in Office 2007 and utilizing XML and ZIP technologies, offers improved efficiency and security features.
Developer	🔵 Microsoft
MIME type	🔵 application/vnd.ms-excel

Office Open XML Document

Extension	.xlsx
Category	🔵 documents
Programs	🔵 Microsoft Office 🔵 LibreOffice 🔵 Kingsoft Office 🔵 Google Docs
Main program	🔵 Microsoft Office
Description	🔵 .xlsx (Microsoft Excel Open XML Spreadsheet) The .xlsx format is the default file format for spreadsheets created in Microsoft Excel, starting with Excel 2007 and later versions. It is a part of the Office Open XML specification and utilizes XML and ZIP compression to reduce file sizes. The .xlsx format allows for the creation of complex spreadsheets containing data, formulas, charts, pivot tables, and various formatting options. It is more efficient and secure when compared to the older .xls format, and is widely utilized in business, education, and personal data management.
Technical details	🔵 Introduced in Excel 2007 as part of the Office Open XML (OOXML) standard, the `.xlsx` format represents a significant advancement from the older `.xls` format. It utilizes XML within a ZIP archive structure to enhance data readability and efficiently organize elements such as worksheets and shared strings. This format can handle extensive datasets, supporting up to 1,048,576 rows and 16,384 columns per sheet. Additionally, it includes advanced features like formulas, charts, pivot tables, and VBA macros. The use of shared XML files helps optimize file size. `.xlsx` promotes cross-platform interoperability, integrates security features such as digital signatures and encryption, and even offers a macro-enabled `.xlsm`
Developer	🔵 Microsoft
MIME type	🔵 application/vnd.openxmlformats-officedocument.spreadsheetml.sheet