Removing Comments and Track Changes from Excel Files

Why Comments and Track Changes Are a Privacy Risk

Comments and Track Changes are collaboration tools designed for internal use. They let team members annotate cells with context, flag questions, and maintain a detailed audit trail of every insertion, deletion, and format change. The problem arises when these internal artifacts travel with the file to an external recipient who was never meant to see them.

Unlike visible cell data, comments and revision history sit in background layers of the spreadsheet. Users often forget they exist because they are not part of the primary grid view. A file that looks perfectly clean on screen may contain dozens of comments with candid internal assessments and a complete revision log showing every value that was changed, who changed it, and when.

Each of these scenarios could have been avoided by removing comments and Track Changes before the file left the organization. The following sections cover every type of annotation and revision data in Excel and how to eliminate them.

Understanding Comments, Notes, and Threaded Discussions

Excel has evolved its annotation features over time, and the terminology can be confusing. Modern versions of Excel (Microsoft 365) distinguish between three types of cell-level annotations:

All three types embed the author’s identity, and all three travel with the file when shared. Even if you have stripped the document properties (Title, Author, Company), the author attribution within individual comments and notes remains intact. This means a file you thought was anonymized may still reveal exactly who wrote each annotation.

Understanding Track Changes and Revision History

Track Changes is Excel’s built-in feature for recording every edit made to a workbook. When enabled, it logs the cell address, old value, new value, author, timestamp, and type of change (insertion, deletion, or modification) for every edit. This revision log is stored inside the file and persists until explicitly removed.

In older Excel formats (.xls), Track Changes data was stored in a hidden “revision log” stream within the binary file. In modern .xlsx files, revision data is stored in the xl/revisions/ folder inside the ZIP package. Shared workbooks (the legacy co-authoring model) maintain a particularly detailed revision history that can span thousands of changes.

Removing Comments and Notes on Windows

Windows offers several approaches to removing comments and notes, ranging from manual methods for individual files to the Document Inspector for comprehensive cleanup.

The Document Inspector is the recommended approach because it scans the entire workbook at once, including all sheets, and can remove multiple types of hidden data in a single operation. Manual deletion is error-prone because it requires you to remember to check every sheet individually.

Removing Comments and Notes on Mac

Excel for Mac has the same core functionality but with slightly different menu paths and some limitations in older versions.

Removing Track Changes and Revision History

Removing Track Changes requires a different approach than removing comments. Simply turning off Track Changes does not delete the existing revision history — you must explicitly accept or reject all changes, and in some cases take additional steps to purge the revision log.

Using VBA for Automated Removal

For workbooks with many sheets or when you need to process multiple files, VBA macros provide a reliable way to remove all comments and notes programmatically. This eliminates the risk of missing a sheet during manual cleanup.

Sub RemoveAllCommentsAndNotes()
    Dim ws As Worksheet
    Dim commentCount As Long

    commentCount = 0

    For Each ws In ThisWorkbook.Worksheets
        ' Remove legacy comments/notes
        Dim c As Comment
        For Each c In ws.Comments
            commentCount = commentCount + 1
            c.Delete
        Next c
    Next ws

    MsgBox "Removed " & commentCount & " comments/notes " & _
           "from all sheets.", vbInformation
End Sub

Sub RemoveTrackChanges()
    On Error Resume Next

    ' Accept all tracked changes
    ThisWorkbook.AcceptAllChanges

    ' Turn off change tracking
    If ThisWorkbook.KeepChangeHistory Then
        ThisWorkbook.KeepChangeHistory = False
    End If

    ' Unshare if shared
    If ThisWorkbook.MultiUserEditing Then
        ThisWorkbook.ExclusiveAccess
    End If

    On Error GoTo 0

    MsgBox "Track Changes removed and change " & _
           "tracking disabled.", vbInformation
End Sub

Using Python for Batch Processing

When you need to clean comments from many files at once — such as before a bulk file transfer or as part of a data release pipeline — Python with the openpyxl library provides a scriptable solution.

import openpyxl
from pathlib import Path

def remove_comments(file_path: str, output_path: str) -> dict:
    """Remove all comments from an Excel file."""
    wb = openpyxl.load_workbook(file_path)
    stats = {"sheets": 0, "comments_removed": 0}

    for ws in wb.worksheets:
        stats["sheets"] += 1
        for row in ws.iter_rows():
            for cell in row:
                if cell.comment:
                    stats["comments_removed"] += 1
                    cell.comment = None

    wb.save(output_path)
    wb.close()
    return stats

# Process all .xlsx files in a directory
input_dir = Path("./input")
output_dir = Path("./output")
output_dir.mkdir(exist_ok=True)

for xlsx_file in input_dir.glob("*.xlsx"):
    out_path = output_dir / xlsx_file.name
    result = remove_comments(str(xlsx_file), str(out_path))
    print(f"{xlsx_file.name}: removed "
          f"{result['comments_removed']} comments "
          f"from {result['sheets']} sheets")

Verifying Removal at the XML Level

The most thorough way to verify that all comments and Track Changes have been removed is to inspect the raw XML inside the XLSX file. This catches anything that the GUI tools or libraries might miss, including threaded comments and orphaned revision logs.

If any of these files remain after your cleanup, you can delete them from the ZIP archive and re-save as .xlsx. However, you must also update the relationship files ([Content_Types].xml and the relevant .rels files) to remove references to the deleted files, or Excel may report the file as corrupt when opening it.

Using MetaData Analyzer to Check for Comments and Track Changes

Our free online tool provides instant visibility into the comments, notes, and revision metadata embedded in your Excel files. Upload your file and the analyzer will report all detected annotations, including the author name associated with each comment, threaded discussion threads, and any Track Changes revision data.

This gives you a clear picture of what needs to be removed before sharing, without manually inspecting each sheet or digging through XML. Use it as a final verification step after running the Document Inspector or your cleanup script to confirm that nothing was missed.

Pre-Sharing Checklist

Use this checklist every time you prepare an Excel file for external sharing. Work through each item systematically to ensure no comments, notes, or revision data travel with the file.

Preventing Future Accumulation

Rather than cleaning up comments and Track Changes every time you share a file, consider establishing workflows that minimize their accumulation in the first place.

Conclusion

Comments, notes, and Track Changes are essential collaboration features, but they become liabilities the moment a file leaves your organization. They expose author identities, internal discussions, negotiation strategies, and the complete history of every edit — information that recipients can access with no specialized tools.

The key takeaway is that turning off Track Changes or closing the comments pane does not remove the data. You must actively delete comments, accept all tracked changes, disable change tracking, and ideally Save As a new file to ensure a clean slate. The Document Inspector, VBA macros, Python scripts, and XML-level inspection each provide different levels of thoroughness depending on your needs.

Make comment and Track Changes removal a standard step in your file-sharing workflow. Use our MetaData Analyzer as a final verification to confirm your files are truly clean before they reach anyone outside your organization.