ExifTool supports reading and writing PDF documents up to version 2.0,
including support for RC4, AES-128 and AES-256 encryption. A
Password option is provided to allow processing
of password-protected PDF files.
ExifTool may be used to write native PDF and XMP metadata to PDF files. It
uses an incremental update technique that has the advantages of being both
fast and reversible. If ExifTool was used to modify a PDF file, the
original may be recovered by deleting the PDF-update pseudo-group (with
-PDF-update:all= on the command line). However, there are two main
disadvantages to this technique:
1) A linearized PDF file is no longer linearized after the update, so it
must be subsequently re-linearized if this is required.
2) All metadata edits are reversible. While this would normally be
considered an advantage, it is a potential security problem because old
information is never actually deleted from the file. (However, after
running ExifTool the old information may be removed permanently using the
"qpdf" utility with this command: "qpdf --linearize in.pdf out.pdf".)
As well as the tags listed below, the PDF specification allows for
user-defined tags to exist in the Info dictionary. These tags, which should
have corresponding XMP-pdfx entries in the XMP of the PDF XML Metadata
object, are also extracted by ExifTool.
Writable specifies the value format, and may be string, date,
integer, real, boolean or name for PDF tags.
Tag ID
Tag Name
Writable
Values / Notes
'AAPL:Keywords'
AppleKeywords
string+
(keywords written by Apple utilities, although they seem to use PDF:Keywords
when reading)
'Author'
Author
string
'CreationDate'
CreateDate
date
'Creator'
Creator
string
'Keywords'
Keywords
string+
(stored as a string but treated as a comma- or semicolon-separated list of
items when reading if the string contains commas or semicolons, whichever is
more numerous, otherwise it is treated a space-separated list of items. The
list behaviour may be defeated by setting the API NoPDFList option. Written
as a comma-separated string. Note that the corresponding XMP-pdf:Keywords
tag is not treated as a list, so the NoPDFList option should be used when
copying between these two.)
--> PostScript Tags (the ExtractEmbedded option enables information to be extracted from embedded
PostScript documents in the AIPrivateData# and AIPDFPrivateData# streams)
Information extracted from embedded images with the ExtractEmbedded option.
The EmbeddedImage and its metadata are extracted only for JPEG and Jpeg2000
image formats.
(FieldMDP signatures only) 'All' = Disallow changes to all form fields
'Exclude' = Allow changes to specified form fields
'Include' = Disallow changes to specified form fields
'Annots'
AnnotationUsageRights
no+
(possible values are Create, Delete, Modify, Copy, Import and Export;
additional values for UR3 signatures are Online and SummaryView)
'Document'
DocumentUsageRights
no+
(only possible value is FullSave)
'EF'
EmbeddedFileUsageRights
no+
(possible values are Create, Delete, Modify and Import)
'Fields'
FormFields
no+
(FieldMDP signatures only)
'Form'
FormUsageRights
no+
(possible values are FillIn, Import, Export, SubmitStandalone and
SpawnTemplate; additional values for UR3 signatures are BarcodePlaintext and
Online)
'FormEX'
FormExtraUsageRights
no+
(UR signatures only; only possible value is BarcodePlaintext)
'Msg'
UsageRightsMessage
no
'P'
ModificationPermissions
no
(1-3 for DocMDP signatures, default 2; true/false for UR3 signatures, default
false) 1 = No changes permitted
2 = Fill forms, Create page templates, Sign
3 = Fill forms, Create page templates, Sign, Create/Delete/Edit annotations
'false' = Do not restrict applications to reader permissions
'true' = Restrict all applications to reader permissions
'Signature'
SignatureUsageRights
no+
(only possible value is Modify)
(This document generated automatically by Image::ExifTool::BuildTagLookup)
Last revised May 29, 2026
