XLS to XLSXConverter — Fast & Free Online
Batch XLS to XLSX conversion with per-file progress tracking. XLSX format offers feature-rich.
How XLS to XLSX Conversion Works
The XLS file format stores data in the XLS format. Converting to XLSX produces a spreadsheet file that stores cell values, formulas, formatting, and charts as zipped XML, the default format for Microsoft Excel 2007 and later. This conversion changes the file's encoding, compression method, and supported feature set. Cell values and structure are preserved; formulas are evaluated to their computed values in plain-text target formats. This makes XLSX the practical choice when the destination system requires it or when the target format offers better compatibility or compression. 1converter runs this conversion on the server: your file is uploaded encrypted over HTTPS, converted using trusted open-source libraries, and the output is held for 24 hours before automatic deletion.
How to Convert XLS to XLSX
Follow these simple steps to convert your XLS files to XLSX format in seconds
Step 1
Drop your XLS file into the box above or pick it from your device
Step 2
Confirm XLSX as the target format
Step 3
Keep the original layout, fonts, and images in the XLSX file
Step 4
Start the conversion and watch the live progress
Step 5
Download the finished XLSX file — it is deleted from our servers after 24 hours
Average conversion time: Less than 2 minutes
Visual Conversion Preview
Source file
Converting...
~1s
Output file
This visualization shows the typical conversion process from XLS to XLSX format, including expected size reduction and quality retention.
Why Convert XLS to XLSX?
Discover the advantages of converting your XLS files to XLSX format
XLSX provides charts
Free XLS to XLSX conversion online
Preserve formulas in XLSX output
No software installation needed for XLS to XLSX
XLS offers smaller than xlsx
Additional Features
Popular Use Cases
See how professionals use our XLS to XLSX converter in real-world scenarios
XLS files for financial reports
Convert XLS to XLSX for this purpose quickly and easily.
Survey data exported to XLSX
Convert XLS to XLSX for this purpose quickly and easily.
Inventory lists converted to XLSX
Convert XLS to XLSX for this purpose quickly and easily.
Financial reports exported as XLSX
Convert XLS to XLSX for this purpose quickly and easily.
XLS files for budgets
Convert XLS to XLSX for this purpose quickly and easily.
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Frequently Asked Questions
Everything you need to know about converting XLS to XLSX
Still Have Questions?
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