Hidden data in Word, Excel and PowerPoint: the kinds Document Inspector checks, what it leaves behind, and how to check by hand

Last updated: 4 October 2026

Short answer: besides the text and tables on screen, an Office file can carry comments, tracked changes, properties such as the author's name, hidden text, hidden sheets, rows and columns, objects placed off the slide, speaker notes and the source data behind pivot tables. On Windows, Office's Document Inspector looks for these. Microsoft itself lists things it cannot detect, and in Excel a set of things it finds but will not remove. Word for Mac has no document inspector at all.

The lists below come from Microsoft's own pages, mainly Remove hidden data and personal information by inspecting documents, presentations, or workbooks (called "Microsoft's article" below) and Inspect document. They are the kinds Microsoft names, not every place a file can keep data.

Two recent cases from Japan

Published workbooks with a sheet nobody looked at are not only a British problem. In August 2026 the city of Okawa in Fukuoka announced (in Japanese) that a list of local welfare volunteers it had put on its website as an Excel file in December 2025 contained a hidden sheet. Unhiding it showed earlier lists with the names and phone numbers of 188 people. A resident pointed it out by email. When the city replaced the file with a PDF, it found that the Excel file was still on its website system and could be opened by changing the PDF address's extension to xlsx.

In March 2026 the Tokyo Para Sports Association reported (in Japanese) that an Excel file it had posted to recruit course participants held a hidden sheet with earlier applicants' details, including dates of birth, addresses, phone numbers and whether they had a disability, for 366 people. It came to light through an email from a past applicant, and the association found that the information could be viewed through search engine results. Our Japanese article covers these and a third case, and the FOI leaks guide covers the UK ones.

Word documents

Microsoft's article lists these Word inspectors:

Comments, Revisions, Versions, and Annotations: comments, revision marks from tracked changes, document version information and ink annotations. Deleted text stays in the file as a tracked deletion until the change is accepted or rejected; our tracked changes guide explains what that does to the text.
Document Properties and Personal Information: the Summary, Statistics and Custom tabs of the properties dialog, email headers, routing slips, send-for-review information, the user name and the template name, among others.
Headers, Footers, and Watermarks.
Hidden Text: text formatted as hidden with the font effect in the Font dialog.
Custom XML Data and Invisible Content (objects formatted as invisible).

Two notes in the same table matter. The hidden text inspector "cannot detect text that was hidden by other methods (for example, white text on a white background)", and the invisible content inspector "cannot detect objects that are covered by other objects".

Excel workbooks

Comments and annotations.
Document properties and personal information: as in Word, plus printer path information, scenario comments, the file path for publishing web pages, comments for defined names and table names, and inactive external data connections.
Headers and footers.
Hidden rows and columns, and hidden worksheets.
Custom XML data and invisible content.

Excel is where the gaps are widest. Microsoft's article has a section headed "Information the Document Inspector finds but can't remove": items that "might have data that isn't visible", which it leaves in place "because it might cause the workbook to not work properly". They are external links (in cells, names, shapes, chart titles and chart data series), embedded files and objects, macros and VBA code, BI features with cached data (PivotTables and PivotCharts, slicers and timelines, cube formulas), Excel Surveys, Scenario Manager scenarios, filters and hidden names. You are expected to examine each one and remove it yourself, or replace it with something that holds no data, such as a static picture.

There are three further caveats in the Excel table. Document Inspector "doesn't detect shapes, charts, controls, Microsoft ActiveX objects and controls, pictures, or SmartArt graphics that might be located in hidden columns". Hidden rows or columns that are part of a table header, list header or PivotTable are not removed but unhidden. And removing hidden rows, columns or worksheets that contain data "might change the results of the calculations or formulas in your workbook".

On hidden sheets specifically, Microsoft's page Hide or unhide worksheets adds that sheets hidden by VBA code have the property xlSheetVeryHidden, and "the Unhide command will not display those hidden sheets".

PowerPoint presentations

Comments and annotations.
Document properties and personal information, including the file path for publishing web pages.
Revision tracking data: who has edited the file and when.
Invisible on-slide content, again without objects covered by other objects.
Off-slide content: clip art, text boxes, graphics and tables outside the slide area. Microsoft notes that the inspector "does not detect or remove off-slide objects with animation effects".
Presentation notes: the text of the notes. It "cannot remove pictures that are added to the Notes section".
Custom XML data.

Microsoft's article also gives an example of version mismatch: revision tracking data added by a newer PowerPoint for Microsoft 365 cannot be detected or removed by the Document Inspector of an earlier version. What the inspector checks depends on the version you run it in.

Running Document Inspector on Windows

Save a copy. Microsoft "highly recommend[s]" inspecting a copy, "because it is not always possible to restore the data that the Document Inspector removes".
In the copy, on the File tab, select Info.
Select Check for Issues, then Inspect Document.
Tick the kinds of content to inspect and select Inspect.
Review the results and select Remove All next to each kind you want gone.

On a Mac and on the web

Microsoft's Inspect document page says that Word for Mac "doesn't have a document inspector" and offers the manual route instead: File › Properties, then the Summary and Custom tabs, where custom properties can be selected and deleted. The same page says that viewing or changing document properties "isn't currently possible in Word for the web".

We could not find a Microsoft page that says whether Excel or PowerPoint for Mac have a document inspector, so we do not claim either way. If your copy has no Check for Issues, it does not have one. What you can still do by hand:

Word: on the Review tab, accept or reject every tracked change, then delete the comments. Microsoft's page Accept or reject tracked changes in Word warns that the No Markup view "only temporarily hides changes".
Excel: the Hide or unhide worksheets page applies to Excel for Microsoft 365 for Mac and has macOS steps; the Unhide dialog lists hidden sheets, except very hidden ones. Look for gaps in row numbers and column letters, and scroll well past the visible table.
PowerPoint: read the notes of every slide and look around the edges of each slide in normal view.

Not on the list

Some data that says something about a file's history is not a kind Document Inspector names. Word records editing-session identifiers, covered in our rsid guide. Photos placed in a document can keep their own metadata, such as the date taken or the place.

And data that is in the file but not hidden is beyond any inspector: a table far to the right of the visible one, white text, a shape under another shape. If a table of numbers is all the recipient needs, sending it as a PDF or HTML page — the step Okawa now asks of its staff — avoids the question. Saving as CSV also leaves the other sheets behind: Microsoft's page on importing and exporting text files says Excel reminds you "that only the current worksheet will be saved to the new file".

Where ScrubDrop fits

ScrubDrop reads .docx, .xlsx and .pptx files in your browser — nothing is uploaded — and lists, for free, the kinds above along with editing-session identifiers, image metadata and extension data it does not recognise. White or tiny text and cells outside the print area are pointed out but not removed. It works the same on a Mac.

To remove what it found, it rebuilds the file from the parts it knows are needed, then reads the result again with different parsers to check that nothing of the kinds you chose is left and that the visible content has not changed. A file that fails that check is not offered. The free version removes properties, comments and tracked changes (by accepting them), one file at a time. Removing hidden sheets, notes, off-slide objects and the other structural kinds, rejecting tracked changes, and handling several files at once are part of ScrubDrop Pro.

ScrubDrop does not judge whether visible text is confidential and does not read text inside images. The re-check is a strong signal, not a promise: open the result and look before you send it.

Questions

Where is Document Inspector?

In Word, Excel and PowerPoint on Windows: on the File tab, select Info, then Check for Issues, then Inspect Document. Microsoft recommends running it on a copy, because it is not always possible to restore the data it removes.

Does Word for Mac have Document Inspector?

No. Microsoft's Inspect document page says Word for Mac doesn't have a document inspector and describes checking properties by hand through File › Properties instead.

Does Document Inspector remove every kind of hidden data from an Excel workbook?

No. According to Microsoft's article, it finds but does not remove external links, embedded files, macros and VBA code, and BI features with cached data such as PivotTables, among others. It does not detect shapes and pictures in hidden columns, or objects covered by other objects.

See what an Office file holds before you send it. Free: one file at a time; every kind of hidden data is listed, and properties, comments and tracked changes are removed. Removing the structural kinds, and several files at once, is part of ScrubDrop Pro. Check a file.