PDF - remove all metadata

[exft]

Hello, just found ExifTool and seems it's great. I tried to remove metadata from one PDF file but I still see metadata like "Writer Name", "Reader Name", "Software" etc.

BEFORE

Code Select Expand

exiftool example.pdf

...
Has Real Merged Data            : Yes
Writer Name                     : Adobe Photoshop
Reader Name                     : Adobe Photoshop 2023
Exif Byte Order                 : Big-endian (Motorola, MM)
Software                        : Adobe Photoshop 24.0 (Windows)
Modify Date                     : 2023:02:20 15:36:35
Color Space                     : sRGB
Exif Image Width                : 13222
Exif Image Height               : 9585
Compression                     : JPEG (old-style)
Thumbnail Offset                : 306
Thumbnail Length                : 0
Creator                         : Adobe Scan for Android 23.01.17-regular
...
AFTER (used exiftool -all= example.pdf)

Code Select Expand

exiftool example.pdf

...
Has Real Merged Data            : Yes
Writer Name                     : Adobe Photoshop
Reader Name                     : Adobe Photoshop 2023
Exif Byte Order                 : Big-endian (Motorola, MM)
Orientation                     : Horizontal (normal)
Resolution Unit                 : inches
Software                        : Adobe Photoshop 24.0 (Windows)
Modify Date                     : 2023:02:20 15:36:35
Color Space                     : sRGB
Exif Image Width                : 13222
Exif Image Height               : 9585
Compression                     : JPEG (old-style)
Thumbnail Offset                : 306
Thumbnail Length                : 0
Creator                         : Adobe Scan for Android 23.01.17-regular
Any way to remove everything like Writer, Reader etc?
Thank you very much.

[Phil Harvey]

You did see this warning when you tried to delete all metadata from a PDF, right?:

Code Select Expand

Warning: [minor] ExifTool PDF edits are reversible. Deleted tags may be recovered!
(I just want to be sure we're on the same page here.)

The tags you mention are contained deep within some Photoshop resources in the file, which currently aren't writable using ExifTool.  ExifTool currently writes only PDF Info and XMP tags to PDF files.  (See the 3rd paragraph in the ExifTool PDF Tags documentation.)

- Phil

[exft]

yes correct, I see that message.
Any other way to delete that tags too please?

[Phil Harvey]

I don't know a way.

- Phil