Free online XLS to XLSX converter
Convert legacy XLS spreadsheets to editable XLSX files with Excel, LibreOffice, or 101convert.com.
Convert XLS to XLSX online - free
Your file is processed instantly and never stored on our servers.
Import a file from a URL
Paste a direct link to the file. We download it to our server and it is converted exactly like an upload.
How it works
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Upload your .xls file
Click to browse to select your file you want to convert or simply drag & drop your file into selected area.
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Perform .xls to .xlsx conversion
After successful file upload, click to convert when you are ready.
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Download converted .xlsx file
Conversion result is ready to download.
How to convert xls to xlsx file
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Older accounting systems, reports, and spreadsheet archives often produce .xls files that newer software handles poorly or refuses to open. Converting them to .xlsx improves compatibility, usually reduces size, and preserves an editable workbook for current applications.
What the XLS format is
.xls is Microsoft Excel’s binary workbook format used by Excel 97–2003 and many older spreadsheet programs. It can contain worksheets, formulas, charts, formatting, named ranges, external links, and VBA macros.
Each worksheet is limited to 65,536 rows and 256 columns. The binary format cannot represent some features introduced in newer Excel versions and is less convenient for modern spreadsheet libraries and automated processing.
What the XLSX format is
.xlsx is the XML-based workbook format used by Microsoft Excel 2007 and later, LibreOffice Calc, and most current spreadsheet software. Each worksheet supports up to 1,048,576 rows and 16,384 columns, with support for modern formulas, tables, charts, conditional formatting, and cell styles.
An XLSX file is a ZIP package containing XML documents and related resources. It is often smaller than the equivalent XLS file and is easier for software to inspect, generate, and process. XLSX cannot retain VBA macros; a workbook that must keep VBA should be saved as .xlsm.
Convert with Microsoft Excel
- Open the
.xlsfile in the desktop version of Excel. - Review any compatibility warning before saving.
- Choose File → Save As, select a folder, and set the file type to
Excel Workbook (*.xlsx). - Use a new filename if the original must remain unchanged, then select Save.
- If Excel asks whether to keep the workbook in the selected format, confirm the XLSX option.
For several files, LibreOffice’s command-line mode is generally more suitable than manually opening each workbook. Excel automation through VBA or PowerShell is also possible, but test it on copies because links, protected sheets, macros, and dialog prompts can interrupt batch processing.
Convert with LibreOffice Calc
- Open the file in Calc.
- Choose File → Save As.
- Select
Excel 2007–365 (*.xlsx)or the equivalent XLSX option shown by your version. - Save the file and confirm that Calc should use the selected Excel format.
For a command-line conversion, create the destination directory first and run:
libreoffice --headless --convert-to xlsx --outdir converted input.xlsLibreOffice normally writes input.xlsx to the converted directory. The exact command may be soffice instead of libreoffice, depending on the installation.
Convert without installing software
You can convert the file for free on 101convert.com by uploading the .xls file, selecting XLSX as the output format, starting the conversion, and downloading the result. Do not upload confidential payroll, financial, medical, or personally identifiable data unless the service’s current privacy and retention terms are acceptable.
Check the converted workbook
Conversion changes the file format but does not guarantee identical behavior. Compare important worksheets with the original and check formulas, calculated values, named ranges, charts, print areas, page breaks, external links, hidden sheets, merged cells, conditional formatting, and embedded objects.
Excel or Calc may alter unsupported formatting, legacy formulas, chart properties, page settings, or objects. Recalculate the workbook and inspect it in the software that will be used for editing or distribution.
If the original file contains VBA, do not save it as .xlsx when the macros are needed: use Excel Macro-Enabled Workbook (*.xlsm) instead. Also verify password protection, digital signatures, external data connections, and legacy add-ins, because these may not transfer or may require reconfiguration after conversion.
XLS vs XLSX: format comparison
How the XLS and XLSX formats compare on the properties that matter most for this conversion.
| Property | .XLS Microsoft Excel Spreadsheet | .XLSX Microsoft Excel Open XML Spreadsheet |
|---|---|---|
| Editable text | No | No |
| Fixed page layout | No | No |
| Text formatting | Extensive | Extensive |
| Images | Limited | Yes |
| Interactive elements | Yes | Yes |
| Password protection | Basic | Basic |
| Opens in a web browser | Partial | Partial |
| Typical file size | Medium | Medium |
| Open standard | No | Yes |
| Best used for | Data exchange | Data exchange |
| Introduced | 1987 | 2007 |
| Developer | Microsoft | Microsoft |
| MIME type | application/vnd.ms-excel | application/vnd.openxmlformats-officedocument.spreadsheetml.sheet |
Suggested software and links: xls to xlsx converters
Frequently asked questions
Is the XLS to XLSX converter free?
Yes, converting XLS to XLSX on 101convert.com is completely free. No registration, email address or installation is required. If you need a higher file size limit or want to convert more files at once, see our plans.
How large can my XLS file be?
You can upload XLS files up to 1000 MB and convert up to 100 files at once in a single batch.
What happens to my uploaded files?
Files are processed automatically and deleted from our servers within a few minutes after conversion. We never view or share your files.
Do I need to install any software to convert XLS to XLSX?
No. The XLS to XLSX conversion runs entirely online in your browser and works on Windows, Mac, Linux, Android and iPhone.
Did the conversion fail?
In most cases, the cause is an incorrect file format. Please upload a valid XLS file for this XLS to XLSX conversion. Occasionally, the issue may be on our side. We analyze recurring conversion failures and disable or fix the converter if we detect a defect.
Additional formats for
xls file conversion
- xls to xlsm
- xls to visio
- xls to txt
- xls to wps
- xls to mpp
- xls to mp3
- xls to jpg
- xls to ascii
- xls to docx
- xls to vsd
- xls to accdb
- xls to csv
- xls to doc
- xls to gsheet
- xls to htm
- xls to numbers
- xls to ods
- xls to odt
- xls to pages
- xls to pdf
- xls to pmd
- xls to png
- xls to ppt
- xls to rtf
- xls to sam
- xls to sdw
- xls to slk
- xls to sql
- xls to stw
- xls to tdl
- xls to tiff
- xls to tns
- xls to vcf
- xls to webp
- xls to wk1
- xls to wk4
- xls to wri
- xls to wsd
- xls to xlsb
- xls to xlt
- xls to xml
- xls to xps
Reverse conversion
Convert to xlsx from
other formats
- rpt to xlsx
- dat to xlsx
- _xls to xlsx
- xlsm to xlsx
- pmdx to xlsx
- rtf to xlsx
- csi to xlsx
- spv to xlsx
- pptx to xlsx
- xlb to xlsx
- 123 to xlsx
- bak to xlsx
- csv to xlsx
- cwk to xlsx
- dif to xlsx
- doc to xlsx
- docx to xlsx
- et to xlsx
- excel to xlsx
- exe to xlsx
- fp5 to xlsx
- gsheet to xlsx
- htm to xlsx
- html to xlsx
- jpeg to xlsx
- jpg to xlsx
- jrprint to xlsx
- mdf to xlsx
- mpp to xlsx
- numbers to xlsx
- odc to xlsx
- ods to xlsx
- odt to xlsx
- ofx to xlsx
- ots to xlsx
- oxps to xlsx
- pages to xlsx
- pdf to xlsx
- pmd to xlsx
- png to xlsx
- prnx to xlsx
- pxl to xlsx
- qpw to xlsx
- qrp to xlsx
- sb3 to xlsx
- sdw to xlsx
- shs to xlsx
- slk to xlsx
- sta to xlsx
- stw to xlsx
- sxc to xlsx
- tif to xlsx
- tiff to xlsx
- tsv to xlsx
- vsd to xlsx
- vvv to xlsx
- wb1 to xlsx
- wb2 to xlsx
- wb3 to xlsx
- wbd to xlsx
- wk1 to xlsx
- wk3 to xlsx
- wk4 to xlsx
- wks to xlsx
- wq1 to xlsx
- xlk to xlsx
- xlsb to xlsx
- xlt to xlsx
- xltx to xlsx