How to Remove "Last Modified By" Information in PowerPoint for Mac
Question details
The user wants to completely anonymize a PowerPoint presentation by removing the "Last Modified By" author details, as well as the creation and modification dates.
- Product
- Microsoft PowerPoint
- Device & OS
- macOS
- Scenario
- Preparing a presentation for sharing or distribution where personal metadata and file editing history need to be hidden securely.
- Observed behavior
- The "Last Modified By" name and operating-system-level timestamps (creation/modification dates) remain embedded in the file and cannot easily be cleared using standard PowerPoint menus alone.
Create a secure backup copy of your PowerPoint presentation before attempting to modify system-level metadata or running VBA scripts, as these changes are often irreversible.
Change File Creation and Modification Dates using Mac Terminal
Since Office applications cannot clear operating system timestamps, use the macOS Terminal to manually override the creation and modification dates.
Creation and modification dates are bound to the operating system's file management system, not the presentation content itself. Altering these dates requires using a basic Terminal command.
Press Command + Space to open Spotlight Search, type "Terminal", and press Return to open the application.
Type the command `touch -t YYYYMMDDhhmm` (for example, type `touch -t 202301011200` to set the date to January 1, 2023, at 12:00 PM). Ensure you type a single space after the final digit, but do not press Return yet.
Open Finder, locate your PowerPoint file, and drag it directly into the Terminal window. The exact file path will automatically populate at the end of your command.
Press Return. The file's operating system modification and creation dates will immediately update to the specified timestamp.
Clear "Last Modified By" via Document Properties and VBA
PowerPoint allows you to manually clear standard author fields, while a short VBA macro can definitively overwrite hidden modifier properties.
Easily Protect and Manage Presentation Metadata with WPS Office
Managing document properties doesn't have to require complex Terminal commands. WPS Presentation offers a secure, streamlined way to inspect your slides and manage personal information before you share them with colleagues or clients.
- 1. Open your presentation: Launch WPS Presentation on your Mac and open the .pptx file you wish to anonymize.
- 2. Access File Information: Click on the Menu icon at the top left, select File, and choose Document Properties.
- 3. Clear author data: Navigate to the Summary tab to easily review, edit, or delete the Author, Company, and other identifiable text strings.
- 4. Save a fresh copy: Go to Menu > Save As. Saving the presentation as a completely new file can often generate a fresh, untampered creation date on your operating system.
Frequently Asked Questions
Why can't I just delete the creation date inside PowerPoint?
Creation and modification dates are standard file-system metadata handled directly by the macOS operating system, not the Office application itself. Office software reads these dates but cannot erase them, which is why system-level tools like Finder or Terminal are required.
Does removing personal information from a Mac also remove it for Windows users?
Yes. If you clear the internal document properties (like Author and Last Modified By) within the presentation file and save it, that metadata is removed permanently. It will not be visible when the file is opened on a Windows PC.
Will converting my presentation to a PDF remove the metadata?
Exporting to a PDF usually generates a brand-new file, which sets the creation date to the exact moment of export. However, you should still check the exported PDF's properties, as PowerPoint may pass the original Author name over during the conversion process.
Can I automate the removal of personal information when saving on a Mac?
Depending on your exact version of Office for Mac, you may be able to navigate to PowerPoint > Preferences > Security or Privacy. Some versions include a checkbox labeled "Remove personal information from this file on save" which strips author data automatically upon saving.
