XLSX to XLS Converter
Some systems still only take the Excel 97–2003 format. Upload your .xlsx workbooks and get .xls copies that old Excel versions, legacy import screens and strict upload forms accept.
Data Converter
or drop CSV, TSV, TXT … files here ·
Max 95 MB per file· Up to 20 files· Deleted after 30 minutes
Files are processed on our servers and deleted after 30 minutes.
Character that separates columns in CSV and text files, for both reading and writing. Auto detects it from the input and writes commas.
UTF-8 works for every language. Choose UTF-8 with BOM if Excel on Windows shows garbled accents or Asian characters when opening the CSV.
Excel, ODS and Numbers input: convert the first sheet only, or every sheet (one CSV per sheet in a ZIP, or one JSON key per sheet).
Name of the sheet tab in the new spreadsheet, up to 31 characters.
Array of objects uses column names as keys for every row; array of arrays is more compact and keeps the header as the first array.
Name of the outer element that wraps all rows; each row becomes a <row> inside it.
Used in CREATE TABLE and INSERT statements. Letters, digits and underscores only.
Quoting and column types differ slightly between databases; pick the one you will import into.
Rewrite date cells in one format. ISO (2026-10-18) is safest for databases and code; keep leaves them as they appear in the source.
How to use this tool
- 1
Add the XLSX workbooks
Upload up to 20 .xlsx or .xlsm files, 95 MB each. Check first that no sheet runs past row 65,536 or column IV, the edge of the old grid.
- 2
Choose which sheets go across
All sheets is preselected. Pick First sheet under Sheets to convert when the receiving system reads only the first tab anyway.
- 3
Download the XLS copies
Press Convert to XLS. Each workbook downloads as an .xls file, or as a ZIP when you converted several.
How do I convert XLSX to XLS without Excel?
Upload the .xlsx here and press Convert to XLS. You get an Excel 97–2003 workbook with the same sheets and cell values, as long as each sheet fits within 65,536 rows and 256 columns.
When a system insists on the old XLS format
Excel 2007 changed the default file format, but software that imports spreadsheets did not change with it. An importer written against the binary .xls format reads one specific structure; hand it a ZIP package of XML parts and it fails. That is why some supplier portals, accounting packages and instrument software still say Excel 97–2003 workbook only in their upload instructions.
Converting downward is a compromise, not an upgrade. You give up the larger grid, the bigger color palette and the newer functions in exchange for a file the old system can parse. Keep your .xlsx as the working copy and treat the .xls as an export made for one recipient. When that recipient can take plain text instead, CSV to XLS and its reverse are worth comparing, because CSV avoids most of these limits.
The XLS row limit across Excel versions
- 16,384
Rows per sheet in Excel 5.0 and Excel 95
- 65,536
Rows per sheet in the .xls format of Excel 97–2003
- 1,048,576
Rows per sheet in .xlsx since Excel 2007
Convert XLSX to XLS: what to check first
| Do | Don't |
|---|---|
| Trim each sheet to 65,536 rows and 256 columns or fewer | Rename .xlsx to .xls and hope the importer accepts it |
| Paste formulas as values if the receiver only reads numbers | Expect slicers, sparklines or newer chart types to carry over |
| Shorten text cells that rely on line breaks the importer may not expect | Rely on colors outside the old 56-color palette |
| Open the .xls once in the target system before sending a batch | Delete your .xlsx working copy after converting |
Two numbers explain most surprises. The old format allows 4,000 distinct cell formats per workbook, against 64,000 in XLSX, so a heavily styled report can lose some formatting. And its palette holds 56 colors, so custom brand colors snap to the nearest available one. Data itself, the text, numbers and dates in the cells, carries across unchanged within the grid. If you later need to bring a legacy file forward again, XLS to XLSX does the reverse.
XLSX and XLS compared
XLSX
Microsoft Excel workbook
XLSX is Microsoft Excel's default workbook format since Office 2007, based on the Office Open XML standard. It stores multiple sheets, formulas, formatting, charts, pivot tables and data validation in a ZIP package of XML. It supports over a million rows per sheet and is the default exchange format for business spreadsheets. Google Sheets, LibreOffice and Numbers open XLSX, though macros and advanced features may not carry over.
- Compression
- –
- Transparency
- –
- Animation
- –
- Introduced
- 2007 · Microsoft
XLS
Microsoft Excel 97–2003 workbook
XLS is the binary spreadsheet format used by Excel from Excel 97 until XLSX replaced it in 2007. It is limited to 65,536 rows and 256 columns per sheet and stores data in a proprietary structure. Many legacy systems, government portals and older banking exports still produce or require XLS. Excel, LibreOffice and Google Sheets can open it.
- Compression
- –
- Transparency
- –
- Animation
- –
- Introduced
- 1997 · Microsoft
People step down from XLSX to XLS because a legacy importer, an old Office install or a strict portal only reads the Excel 97–2003 binary format.
XLSX to XLS questions
Who still asks for XLS files?
Mostly software that was built before 2007 and never updated its importer: older ERP and payroll modules, some government and bank upload portals, lab and point-of-sale systems, and people running Office 2003 or earlier. If a form rejects your .xlsx with an invalid file type message, that is usually the reason.
What happens to rows past 65,536?
They have nowhere to go, because the XLS grid ends at row 65,536 and column IV. Split a long sheet into several sheets or files before converting, or send the data as CSV, which has no row limit, if the receiving system accepts it.
Will newer Excel functions survive in an XLS?
Functions introduced after Excel 2003, such as IFERROR in 2007 or XLOOKUP in Microsoft 365, do not exist in the old format. This converter writes cell values, so the XLS shows the last calculated results rather than formulas, which is often exactly what a legacy import expects.
Can Excel 2003 open XLSX at all?
Only with the Microsoft Office Compatibility Pack, a free add-on Microsoft released in 2006 for Office 2000, XP and 2003. Without it the file does not open. The pack is no longer supported, so on a locked-down old machine an .xls copy is the dependable route.
Why is the XLS larger than my XLSX?
XLSX compresses its XML parts inside a ZIP container; XLS stores binary records without that compression. Expect the legacy file to be bigger, sometimes several times bigger for text-heavy sheets, which matters if a portal caps uploads at a few megabytes.