Convert XLS to XLSX
No Signup required, Convert and Download High Qulity XLSX and use anywhere
Powered by Commercial Grade High Quality Excel Algorithms from ExcelMaster.ai. You will notice the higher output quality difference compared to competitors!
Drag & drop up to 10 files here, or click to select files.
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XLS to XLSX Overview
Our free tool allows you to convert Excel files into a variety of formats, offering maximum flexibility for your document conversion needs. It's fully online and compatible with multiple platforms, including Mac OS, Linux, Android, iOS, and more.
How to Convert XLS Files to XLSX
Upload Your Files: Select the Excel files you want to convert and upload them to the website.
Start Conversion: Hit the "Convert" button to initiate the process.
Download: You can immediately download your converted files
File Deletion Notice: Please note that files are automatically deleted from our servers after 24 hours, and download links become inactive after this time.
Key Advantages - XLS to XLSX
No Signup Required
Enjoy hassle-free usage with no sign-up needed. Works smoothly across platforms, including Windows, Mac, iOS, and Android.
Batch File Conversion
Easily convert multiple Excel spreadsheets in one go—upload up to 10 files at a time.
Data Privacy and Security
Your data is secured using advanced encryption methods and is never used for any other purposes. All files are permanently deleted after 24 hours.
Top-Tier, Commercial-Grade Quality
Our conversion algorithms are built with commercial-grade technology, ensuring flawless results even with complex Excel elements like charts and formatting. Although the conversion process is simple for you, our backend is carefully designed to deliver results comparable to leading commercial solutions. Each detail is carefully managed to ensure a premium quality experience.
What is XLSX?
XLSX is a file format used by Microsoft Excel for spreadsheet documents, utilizing a combination of ZIP compression and XML. It allows users to store and organize data in a structured way, including features such as formulas, charts, graphs, and macros. XLSX is commonly used for data analysis, reporting, and data management, particularly when compatibility with modern Excel versions is required.
Data Loss During Conversion
When converting older Excel formats (like XLS) to XLSX, some features such as macros or certain formulas might not convert properly, leading to potential data loss.
Compatibility Issues
Some older versions of Excel do not support XLSX format, which can lead to accessibility problems for users who have not upgraded their software.
Increased File Size
XLSX files can sometimes be larger than their XLS counterparts due to the inclusion of richer data types and features, which may make file sharing more cumbersome.
Corruption Risk
There is a risk of file corruption during the conversion process, especially if the original file is large or contains complex formulas, which can render the file unusable.
What are the differences between XLSX and XLS?
File Format
XLSX is the modern file format used by Microsoft Excel, introduced with Excel 2007, and is based on the Open XML standard. In contrast, XLS is the older binary file format used by earlier versions of Excel up to 2003.
File Size
XLSX files are generally smaller in size compared to XLS files because they use Zipping compression, making it more efficient for storage and sharing.
Data Capacity
XLSX supports a significantly larger amount of data, allowing for up to 1,048,576 rows and 16,384 columns per worksheet, while XLS is limited to 65,536 rows and 256 columns.
Features and Functions
XLSX files support newer features and functions available in Excel 2007 and later versions, such as improved charting tools, Sparklines, and enhanced formulas. XLS files do not have access to these advanced features.