Old XLS files from a previous job, an archived project, or a finance archive. The recipient wants a PDF and you don't have Excel installed on the current machine.
XLS vs XLSX
XLS is Excel's binary format from 1997 to 2003. XLSX is the XML-based format from Excel 2007 onwards. Both still open in modern Excel; both convert to PDF identically.
For recent files, XLSX is the standard. XLS persists in archives and exports from older systems.
Convert without Excel
Flint's Excel to PDF accepts XLS files directly. No Excel installation needed. Drag in, download out.
Useful when you've moved laptops, don't have Office, or just want a one-shot conversion without installing anything.
What to check on old XLS
Old spreadsheets sometimes use macros (XLS files can carry VBA code). Macros don't survive conversion to PDF — only the data values do. If the spreadsheet relies on macros to populate cells, run the macro in Excel first, save the values, then convert.
Old XLS files may also use legacy chart formats. Modern chart conversion handles them but the output may render slightly differently from the original.
Archival considerations
XLS as an archival format is fragile — proprietary binary, dependent on Excel-compatible software. Converting to PDF for archival makes the document much more durable. The PDF will be readable in 50 years regardless of what spreadsheet software exists then.
FAQ
Will macros survive?
No — PDFs don't carry macros. Run macros in Excel first if they're needed, then convert the result.
Should I upgrade XLS to XLSX first?
Not needed for conversion. Upgrade if you'll be editing further in Excel — XLSX has better features and broader compatibility.
What about Excel 95 files?
Very old formats may need a manual open-and-save in modern Excel first. Most XLS from 1997+ converts directly.
Quality difference from XLSX?
None — the PDF output is identical regardless of whether the source was XLS or XLSX.
Old XLS, new PDF. Convert your XLS to PDF without opening Excel.