Short answer
What you need to know
Unhide rows, columns, and worksheets; inspect Name Manager, formulas, comments, links, objects, and properties. A sheet marked very hidden may not appear in Excel's ordinary Unhide dialog and requires deeper inspection.
What a workbook can hide
Excel supports hidden rows, columns, and worksheets. Workbooks can also retain very hidden sheets, defined names, formulas, comments, external links, cached values, properties, and embedded objects.
Templates and calculation models often use these features legitimately.
Manual workbook review
Work on a duplicate, select the entire sheet, and use the row and column Unhide commands.
Unhide worksheets, inspect Name Manager, show formulas, review comments, notes, links, data connections, and objects outside the visible area.
For high-stakes review, use a trusted tool that reports very hidden sheets.
How the scanner helps
Hidden Word Scanner reports hidden and very hidden worksheets, concealed rows and columns, formulas, defined names, comments, links, properties, and embedded objects in supported XLSX workbooks.
Step by step in Excel
Hidden sheets: right-click any sheet tab and choose Unhide. Excel lists every hidden sheet. If the command is greyed out, there are no ordinarily hidden sheets, or the workbook structure is protected.
Hidden rows and columns: look for gaps in the row numbers or column letters, such as a jump from C to F. Select the headers on both sides of the gap, right-click, and choose Unhide. To reveal everything at once, press Ctrl+A, then use Home, Format, Hide and Unhide.
Formulas: press Ctrl+` (the key below Esc) to switch every cell from showing results to showing formulas, and press it again to switch back.
Names and links: open Formulas, Name Manager to list defined names, and Data, Edit Links or Workbook Links to list connections to other files.
Very hidden sheets and cells that only look empty
A sheet can be set to a state called very hidden. It does not appear in the Unhide list, and the usual way to reveal it is through the Visual Basic editor's Properties window, where its Visible setting can be changed back. Model builders use this for lookup tables they do not want edited.
A cell can also hold a value while showing nothing. A custom number format of three semicolons displays an empty cell, and white text on a white fill does the same. Click the cell and read the formula bar, which always shows the real contents.
A worked example
A budget workbook shows a single Summary sheet. Unhide reveals a second sheet named Rates. Showing formulas reveals that the totals on Summary multiply by cells on Rates, and that column D on Summary, which was hidden, holds a set of adjustment figures.
None of that is wrong. It does mean that anyone who receives the file receives the rates and the adjustments too, which is worth knowing before you send it.
Important limitation
Verify important findings
Encrypted files, macros, external data sources, legacy XLS files, and add-ins may require dedicated analysis. Evaluate findings in the workbook's real context.
Further reading
Authoritative references
These primary sources support the concepts and reference information in this guide. Their inclusion does not imply endorsement of Hidden Word Scanner.