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How-To Guide

How to Convert XLS to XLSX

XLS is Excel's binary format from the pre-2007 era. Modern Excel still opens XLS files, but XLSX is the current standard: it supports far more rows (1,048,576 vs 65,536) and columns, and newer Excel features. Excel opens an .xls in Compatibility Mode, which turns those features off. Converting XLS to XLSX future-proofs your spreadsheets.

See what FormatDrop converts
FormatDrop doesn't convert XLS to XLSX yet. The methods below use free tools that do. FormatDrop's own converters cover common image, audio, video and PDF formats, all in your browser.

Other ways to convert XLS to XLSX

  1. 1

    Excel (Windows or Mac)

    Open the .xls file and choose File → Save As → Excel Workbook (.xlsx). On Windows, File → Info → Convert does the same and replaces the old file. Excel keeps formulas, formatting, charts and pivot tables; macros need .xlsm instead.

  2. 2

    LibreOffice Calc (free)

    Open the .xls and choose File → Save As → Excel 2007-365 (.xlsx). For a folder of files: soffice --headless --convert-to xlsx *.xls.

  3. 3

    Google Sheets

    Upload the .xls to Google Drive, open it with Google Sheets, then File → Download → Microsoft Excel (.xlsx). Macros don't carry over.

  4. 4

    Check the result

    Open the .xlsx and check that formulas calculate and charts look right before you delete the .xls.

Why convert XLS to XLSX?

XLS is Excel's legacy binary format. XLSX is the open XML standard that every modern spreadsheet application reads natively. Converting from XLS to XLSX is low-risk, usually seamless, and permanently modernizes your data.

Frequently asked questions

Will macros (VBA) survive XLS to XLSX conversion?
Standard XLSX files do not support VBA macros — you need XLSM (Excel Macro-Enabled Workbook) for that. If your XLS has macros, save as XLSM in Excel (Save As → Excel Macro-Enabled Workbook) to preserve them. Converting to plain XLSX drops the macros.
How do I bulk convert XLS to XLSX with Python?
openpyxl can't read the old .xls format. Use LibreOffice: `soffice --headless --convert-to xlsx *.xls`. Or pandas with the xlrd package, which copies values only: `pd.read_excel('in.xls', sheet_name=None)` returns every sheet for you to write out with `to_excel`.
I have password-protected XLS files — can they be converted?
A file that needs a password to open must be opened with that password first: open it in Excel, then save it as .xlsx. Sheet protection (Review → Unprotect Sheet) is a different thing and doesn't stop conversion. Converters without the password can't read an encrypted file.
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How to Convert CSV to Excel (XLSX)How to Convert XLSX to CSVHow to Convert PDF to ExcelHow to Convert Apple Numbers to Excel XLSX