Quick answer
Drop the .docx into the tool above, which lists the Last modified by value and gives you a copy without it. In Word, Microsoft’s Document Inspector (File, Info, Check for Issues, Inspect Document, then Remove All) handles document properties, but its page does not name this field, so check the properties of the result. Work on a copy, and look at the result before you send it.
Microsoft’s Document Inspector page lists “Document properties” and “Username” among its Word checks. Elsewhere on the same page it says document properties include information “automatically maintained by Microsoft 365 programs, such as the name of the person who most recently saved a document”. That is the same idea as Last modified by, but the page does not use the field name.
What the format and Microsoft say
A .docx is a ZIP package. Microsoft’s archived Learn walkthrough of the Word 2007 XML format (June 2006, Word 2007) says a Word 2007 file consists of a compressed ZIP file called a package, that such a package could contain a docProps folder, and that its core.xml file “Contains common file properties for all files based on the Open Packaging Conventions document format.” Its sample core.xml has a dc:creator element and a cp:lastModifiedBy element, so the creator and the last modifier are two separate elements. That page describes Word 2007 and is archived.
Microsoft’s Open XML SDK reference (version 3.0.1) describes LastModifiedBy as the user who performed the last modification, and adds: “The identification is environment-specific and can consist of a name, email address, employee ID, etc.” So the value is not always a tidy name. It can be an email address or an ID.
On the Word side, Microsoft’s Document Inspector page (Word for Microsoft 365, Word 2021, 2019 and 2016) says: “On the File tab, select Info, choose Check for Issues and select Inspect Document”, then use Remove All next to the results. It warns that “it is not always possible to restore the data that the Document Inspector removes” and that “There is some information that the Document Inspector cannot remove”. The separate Inspect Document page says “Word for Mac doesn’t have a document inspector.”
Microsoft’s privacy options page (Windows versions of Microsoft 365, Office 2021, 2019 and 2016) describes File, Options, Trust Center, Trust Center Settings, Privacy Options, “Remove personal information from file properties on Save”, and says it is turned off in Word. It says the setting removes personal information from the file properties, and gives no field-by-field list. These pages do not say which setting supplies the Last modified by name.
Clean the file with Doc Scrubber
- Keep your original. The tool handles .docx, not the old .doc format and not password-protected files.
- Leave Document properties and personal info ticked. It removes the core properties, including author, last modified by, title and the created, modified and last-printed dates, plus company, manager, template path, custom properties and the preview thumbnail.
- Drop the file on the drop zone, or select Choose files.
- In Found in your file, look for the Last modified by row. It appears only if the file has a value.
- Select Download clean copy. Check Still in the clean copy, which is re-read from the new file, and open the copy yourself.
The file is read in your browser and never uploaded. You can confirm that in the Network tab.
What this does not remove
- Names you can see: body text, headers, footers, signature blocks and watermarks.
- Comments, if you untick the comments option, and tracked changes left in the file, which is the default. Both carry their own author names. The option Replace author names on remaining Word comments and tracked changes with “Author” swaps those names for “Author” on whatever stays.
- Hidden text and document variables. The report lists them, and they stay.
- The file name, macros and embedded objects.
- Signatures: a digital signature stays in the file but stops validating.
- Copies stored elsewhere, such as sent emails and cloud folders.
If you open the clean copy in Word and save it again, check File, Info once more: Microsoft’s Document Inspector page says the name of the person who most recently saved a document is “automatically maintained by Microsoft 365 programs”.
Who should do this before sending
- Lawyers returning a marked-up draft, where the last editor may be a colleague.
- Consultants and freelancers sending a proposal built from an old template.
- Recruiters and HR forwarding files that passed through several hands.
Related guides: remove the author name from a Word document, inspect a document for hidden data, and remove tracked changes and comments from Word.