XLS to XLSX Converter

Convert XLS files to XLSX online for free. Upload a XLS file, choose XLSX, and download the converted file with no account required.

Why convert XLS to XLSX?

Document formats differ in editability, layout stability, table support, and sharing compatibility. XLS files are commonly used for legacy spreadsheets and older Excel workbooks. Converting to XLSX helps when your next tool, device, website, or sharing workflow needs modern spreadsheets, tables, and workbook sharing.

Best uses for XLSX

XLSX is useful for modern spreadsheets, tables, and workbook sharing. XLSX is the modern Excel workbook format. Use this output when compatibility, editing needs, upload requirements, or file size make XLSX the better fit.

Before you convert

Check page order, fonts, spacing, tables, links, images, and whether the converted file opens correctly in your target app. Keep the original XLS file until the converted XLSX file has been reviewed successfully.

Common upload errors this can fix

Use this converter when an upload form says the file type is not supported, when an app cannot preview the XLS file, or when a recipient needs a more familiar XLSX file. Always match the output to the format requested by the destination, especially for job portals, school submissions, marketplace listings, CMS uploads, and social platforms.

XLS vs XLSX

XLS is commonly used for legacy spreadsheets and older Excel workbooks. XLSX is commonly used for modern spreadsheets, tables, and workbook sharing. The best choice depends on whether you need compatibility, editing support, smaller file size, stable layout, transparency, playback support, or a format that a specific upload form accepts.

Conversion checklist

After converting, open the XLSX file before deleting the original XLS. Check file size, readability, playback or preview behavior, and whether the converted file works in the exact app, website, or device where you plan to use it.

XLS to XLSX FAQ

How do I convert XLS to XLSX?

Upload your XLS file, keep XLS as the input format, choose XLSX as the output, then start the conversion and download the converted file.

Is this XLS to XLSX converter free?

Yes. You can convert files online without creating an account or installing desktop software.

When should I use XLSX?

XLSX is useful for modern spreadsheets, tables, and workbook sharing. XLSX is the modern Excel workbook format.

Will converting XLS to XLSX change quality?

Quality depends on the source file and output format. XLS is the older Excel format and is often converted to XLSX, CSV, or PDF. XLSX is the modern Excel workbook format.

Why would a website reject my XLS file?

Many upload forms accept only a short list of formats. If the form asks for XLSX, convert the file first, then open the result and confirm the upload accepts it.

Should I use XLSX for final sharing?

XLSX is useful when the destination needs that format. Use PDF when the document is final and layout stability matters most.

What document details should I review?

Check page breaks, fonts, tables, images, links, headers, footers, and whether scanned text needs OCR before relying on the converted file.