The Excel to PDF tool converts the uploaded workbook with soffice using the calc_pdf_Export filter and passes no sheet-selection or active-sheet-only option, so LibreOffice exports every worksheet tab in the workbook.
Microsoft's support forum explains that Excel's own File > Export to PDF only includes whichever sheet or sheets are currently selected, not the full workbook by default. How can I save as multiple sheets as PDF all at once? And print selected sheets all at once? - Microsoft Q&A
Excel To PDFExcel To PDF All Sheets Or Just One
Upload the Excel workbook to the conversion form.
Wait for the processing to finish before downloading the result.
Checking Sheet Count In The Output
Open the downloaded PDF file.
Count the total pages in the PDF.
Compare the page count against the number of tabs in the original workbook.
Continue with Fixing cut-off columns or Removing blank pages.
Frequently Asked Questions about Excel To PDF All Sheets Or Just One
How do I start the conversion?
Upload the Excel file using the form above.
Where do I find the finished file?
Download the PDF from the results screen.
How do I verify every tab was included?
Count the pages in the PDF and compare the number to the tabs in the workbook.
What if the page count looks wrong?
Review the print area settings in the original Excel file.