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QPDF(1) User Commands QPDF(1)

NAME

qpdf - PDF transformation software

SYNOPSIS

qpdf [ options ] infilename [ outfilename ]

DESCRIPTION

The qpdf program is used to convert one PDF file to another equivalent PDF file. It is capable of performing a variety of transformations such as linearization (also known as web optimization or fast web viewing), encryption, and decryption of PDF files. It also has many options for inspecting or checking PDF files, some of which are useful primarily to PDF developers.

For a summary of qpdf's options, please run qpdf --help. A complete manual can be found at https://qpdf.readthedocs.io.

USAGE (basic invocation)

Read a PDF file, apply transformations or modifications, and write a new PDF file.

Usage: qpdf [infile] [options] [outfile]
OR qpdf --help[={topic|--option}]

•
infile, options, and outfile may be in any order as long as infile precedes outfile.
•
Use --empty in place of an input file for a zero-page, empty input
•
Use --replace-input in place of an output file to overwrite the input file with the output
•
outfile may be - to write to stdout; reading from stdin is not supported
•
@filename is an argument file; each line is treated as a separate command-line argument
•
@- may be used to read arguments from stdin
•
Later options may override earlier options if contradictory

Related Options:

Use in place of infile for an empty input. Especially useful with --pages.
Use in place of outfile to overwrite the input file with the output.
--job-json-file=file

Specify the name of a file whose contents are expected to contain a QPDFJob JSON file. Run qpdf --job-json-help for a description of the JSON input file format.

EXIT-STATUS (meanings of qpdf's exit codes)

Meaning of exit codes:

•
0: no errors or warnings
•
1: not used by qpdf but may be used by the shell if unable to invoke qpdf
•
2: errors detected
•
3: warnings detected, unless --warning-exit-0 is given

Related Options:

Use exit status 0 instead of 3 when warnings are present. When combined with --no-warn, warnings are completely ignored.

COMPLETION (shell completion)

Shell completion is supported with bash and zsh. Use eval $(qpdf --completion-bash) or eval $(qpdf --completion-zsh) to enable. The QPDF_EXECUTABLE environment variable overrides the path to qpdf that these commands output.

Related Options:

Output a command that enables bash completion
Output a command that enables zsh completion

HELP (information about qpdf)

Help options provide some information about qpdf itself. Help options are only valid as the first and only command-line argument.

Related Options:

--help[=--option|topic]

--help: provide general information and a list of topics --help=--option: provide help on a specific option --help=topic: provide help on a topic

Display the version of qpdf.
Display copyright and license information.
Show a list of available crypto providers, one per line. The default provider is shown first.
Describe the format of the QPDFJob JSON input used by --job-json-file.

GENERAL (general options)

General options control qpdf's behavior in ways that are not directly related to the operation it is performing.

Related Options:

--password=password

Specify a password for an encrypted, password-protected file. Not needed for encrypted files without a password.

--password-file=filename

The first line of the specified file is used as the password. This is used in place of the --password option.

Output additional information about various things qpdf is doing, including information about files created and operations performed.
Indicate progress when writing files.
Suppress printing of warning messages. If warnings were encountered, qpdf still exits with exit status 3. Use --warning-exit-0 with --no-warn to completely ignore warnings.
Generate a secure, random document ID only using static information, such as the page contents. Does not use the file's name or attributes or the current time.
Allow creation of files with weak cryptographic algorithms. This option is necessary to create 40-bit files or 128-bit files that use RC4 encryption.
--keep-files-open=[y|n]

When qpdf needs to work with many files, as when merging large numbers of files, explicitly indicate whether files should be kept open. The default behavior is to determine this based on the number of files.

--keep-files-open-threshold=count

Set the threshold used by --keep-files-open, overriding the default value of 200.

ADVANCED-CONTROL (tweak qpdf's behavior)

Advanced control options control qpdf's behavior in ways that would normally never be needed by a user but that may be useful to developers or people investigating problems with specific files.

Related Options:

Provide the underlying file encryption key as a hex-encoded string rather than supplying a password. This is an expert option.
Suppress qpdf's usual behavior of attempting different encodings of a password that contains non-ASCII Unicode characters if the first attempt doesn't succeed.
--password-mode=mode

Fine-tune how qpdf controls encoding of Unicode passwords. Valid options are auto, bytes, hex-bytes, and unicode.

Avoid attempting to recover when errors are found in a file's cross reference table or stream lengths.
Ignore any cross-reference streams in the file, falling back to cross-reference tables or triggering document recovery.

TRANSFORMATION (make structural PDF changes)

The options below tell qpdf to apply transformations that change the structure without changing the content.

Related Options:

Create linearized (web-optimized) output files.
--encrypt [options] --

Run qpdf --help=encryption for details.

Create an unencrypted output file even if the input file was encrypted. Normally qpdf preserves whatever encryption was present on the input file. This option overrides that behavior.
Remove restrictions associated with digitally signed PDF files. This may be combined with --decrypt to allow free editing of previously signed/encrypted files. This option invalidates and disables any digital signatures but leaves their visual appearances intact.
--copy-encryption=file

Copy encryption details from the specified file instead of preserving the input file's encryption. Use --encryption-file-password to specify the encryption file's password.

--encryption-file-password=password

If the file named in --copy-encryption requires a password, use this option to supply the password.

Create a PDF file suitable for viewing in a text editor and even editing. This is for editing the PDF code, not the page contents. All streams that can be uncompressed are uncompressed, and content streams are normalized, among other changes. The companion tool "fix-qdf" can be used to repair hand-edited QDF files. QDF is a feature specific to the qpdf tool. Please see the "QDF Mode" chapter in the manual.
Omit comments in a QDF file indicating the object ID an object had in the original file.
--compress-streams=[y|n]

Setting --compress-streams=n prevents qpdf from compressing uncompressed streams. This can be useful if you are leaving some streams uncompressed intentionally.

--decode-level=parameter

When uncompressing streams, control which types of compression schemes should be uncompressed:

•
none: don't uncompress anything. This is the default with --json-output.
•
generalized: uncompress streams compressed with a general-purpose compression algorithm. This is the default except when --json-output is given.
•
specialized: in addition to generalized, also uncompress streams compressed with a special-purpose but non-lossy compression scheme
•
all: in addition to specialized, uncompress streams compressed with lossy compression schemes like JPEG (DCT) qpdf does not know how to uncompress all compression schemes.
--stream-data=parameter

This option controls how streams are compressed in the output. It is less granular than the newer options, --compress-streams and --decode-level.

Parameters:

•
compress: same as --compress-streams=y --decode-level=generalized
•
preserve: same as --compress-streams=n --decode-level=none
•
uncompress: same as --compress-streams=n --decode-level=generalized
The default generalized compression scheme used by PDF is flate, which is the same as used by zip and gzip. Usually qpdf just leaves these alone. This option tells qpdf to uncompress and recompress streams compressed with flate. This can be useful when combined with --compression-level.
--compression-level=level

Set a compression level from 1 (least, fastest) to 9 (most, slowest) when compressing files with flate (used in zip and gzip), which is the default compression for most PDF files. You need --recompress-flate with this option if you want to change already compressed streams.

--normalize-content=[y|n]

Normalize newlines to UNIX-style newlines in PDF content streams, which is useful for viewing them in a programmer's text editor across multiple platforms. This is also turned on by --qdf.

--object-streams=mode

Control what qpdf does regarding object streams. Options:

•
preserve: preserve original object streams, if any (the default)
•
disable: create output files with no object streams
•
generate: create object streams, and compress objects when possible
Preserve all objects from the input even if not referenced.
--remove-unreferenced-resources=parameter

Remove from a page's resource dictionary any resources that are not referenced in the page's contents. Parameters: "auto" (default), "yes", "no".

Synonym for --remove-unreferenced-resources=no. Use that instead.
For an extra newline before endstream. Using this option enables qpdf to preserve PDF/A when rewriting such files.
If a page has an array of content streams, concatenate them into a single content stream.
Convert inline images to regular images.
--ii-min-bytes=size-in-bytes

Don't externalize inline images smaller than this size. The default is 1,024. Use 0 for no minimum.

--min-version=version

Force the PDF version of the output to be at least the specified version. The version number format is "major.minor[.extension-level]", which sets the version header to "major.minor" and the extension level, if specified, to "extension-level".

--force-version=version

Force the output PDF file's PDF version header to be the specified value, even if the file uses features that may not be available in that version.

PAGE-RANGES (page range syntax)

A full description of the page range syntax, with examples, can be found in the manual. In summary, a range is a comma-separated list of groups. A group is a number or a range of numbers separated by a dash. A group may be prepended by x to exclude its members from the previous group. A number may be one of

•
<n> where <n> represents a number is the <n>th page
•
r<n> is the <n>th page from the end
•
z the last page, same as r1

•
a,b,c pages a, b, and c
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a-b pages a through b inclusive; if a > b, this counts down
•
a-b,xc pages a through b except page c
•
a-b,xc-d pages a through b except pages c through d

You can append :even or :odd to select every other page from the resulting set of pages, where :odd starts with the first page and :even starts with the second page. These are odd and even pages from the resulting set, not based on the original page numbers.

MODIFICATION (change parts of the PDF)

Modification options make systematic changes to certain parts of the PDF, causing the PDF to render differently from the original.

Related Options:

--pages [--file=]file [options] [...] --

Run qpdf --help=page-selection for details.

--file=file

Specify the file for the current page operation. This is used with --pages, --overlay, and --underlay and appears between the option and the terminating --. Run qpdf --help=page-selection for details.

--range=numeric-range

Specify the page range for the current page operation with --pages. If omitted, all pages are selected. This is used with --pages and appears between --pages and --. Run qpdf --help=page-selection for details.

--collate[=n[,m,...]]

Collate rather than concatenate pages specified with --pages. With a numeric parameter, collate in groups of n. The default is 1. With comma-separated numeric parameters, take n from the first file, m from the second, etc. Run qpdf --help=page-selection for additional details.

--split-pages[=n]

This option causes qpdf to create separate output files for each page or group of pages rather than a single output file.

File names are generated from the specified output file as follows:

•
If the string %d appears in the output file name, it is replaced with a zero-padded page range starting from 1
•
Otherwise, if the output file name ends in .pdf (case insensitive), a zero-padded page range, preceded by a dash, is inserted before the file extension
•
Otherwise, the file name is appended with a zero-padded page range preceded by a dash.

Page ranges are single page numbers for single-page groups or first-last for multi-page groups.

--overlay file [options] --

Overlay pages from another file on the output. Run qpdf --help=overlay-underlay for details.

--underlay file [options] --

Underlay pages from another file on the output. Run qpdf --help=overlay-underlay for details.

For each page that is rotated using the /Rotate key in the page's dictionary, remove the /Rotate key and implement the identical rotation semantics by modifying the page's contents. This can be useful if a broken PDF viewer fails to properly consider page rotation metadata.
--flatten-annotations=parameter

Push page annotations into the content streams. This may be necessary in some case when printing or splitting files. Parameters: "all", "print", "screen".

--rotate=[+|-]angle[:page-range]

Rotate specified pages by multiples of 90 degrees specifying either absolute or relative angles. "angle" may be 0, 90, 180, or 270. You almost always want to use +angle or -angle rather than just angle, as discussed in the manual. Run qpdf --help=page-ranges for help with page ranges.

PDF form fields consist of values and appearances, which may be inconsistent with each other if a form field value has been modified without updating its appearance. This option tells qpdf to generate new appearance streams. There are some limitations, which are discussed in the manual.
Attempt to use DCT (JPEG) compression for images that fall within certain constraints as long as doing so decreases the size in bytes of the image. See also help for the following options:
--oi-min-width
--oi-min-height
--oi-min-area
--keep-inline-images
--oi-min-width=width

Don't optimize images whose width is below the specified value.

--oi-min-height=height

Don't optimize images whose height is below the specified value.

--oi-min-area=area-in-pixels

Don't optimize images whose area in pixels is below the specified value.

Prevent inline images from being considered by --optimize-images.
Exclude page labels (explicit page numbers) from the output file.
--set-page-labels label-spec ... --

Set page labels (explicit page numbers) for the entire file. Each label-spec has the form

first-page:[type][/start[/prefix]]

where

•
"first-page" represents a sequential page number using the same format as page ranges: a number, a number preceded by "r" to indicate counting from the end, or "z" indicating the last page
•
"type" is one of - D: Arabic numerals (digits) - A: Upper-case alphabetic characters - a: Lower-case alphabetic characters - R: Upper-case Roman numerals - r: Lower-case Roman numerals - omitted: the page number does not appear, though the prefix,
if specified will still appear
•
"start" must be a number >= 1
•
"prefix"` may be any string and is prepended to each page label

The first label spec must have a first-page value of 1, indicating the first page of the document. If multiple page label specs are specified, they must be given in increasing order.

If multiple page label specs are specified, they must be given in increasing order.

A given page label spec causes pages to be numbered according to that scheme starting with first-page and continuing until the next label spec or the end of the document. If you want to omit numbering starting at a certain page, you can use first-page: as the spec.

Example: "1:r 5:D" would number the first four pages i through iv, then the remaining pages with Arabic numerals starting with 1 and continuing sequentially until the end of the document. For additional examples, please consult the manual.

ENCRYPTION (create encrypted files)

Create encrypted files. Usage:

--encrypt [--user-password=user-password] [--owner-password=owner-password] --bits=key-length [options] --

OR

--encrypt user-password owner-password key-length [options] --

The first form, with flags for the passwords and bit length, was introduced in qpdf 11.7.0. Only the --bits option is is mandatory. This form allows you to use any text as the password. If passwords are specified, they must be given before the --bits option.

The second form has been in qpdf since the beginning and wil continue to be supported. Either or both of user-password and owner-password may be empty strings.

The key-length parameter must be either 40, 128, or 256. The user and/or owner password may be omitted. Omitting either password enables the PDF file to be opened without a password. Specifying the same value for the user and owner password and specifying an empty owner password are both considered insecure.

Encryption options are terminated by "--" by itself.

40-bit encryption is insecure, as is 128-bit encryption without AES. Use 256-bit encryption unless you have a specific reason to use an insecure format, such as testing or compatibility with very old viewers. You must use the --allow-weak-crypto to create encrypted files that use insecure cryptographic algorithms. The --allow-weak-crypto flag appears outside of --encrypt ... -- (before --encrypt or after --).

Available options vary by key length. Not all readers respect all restrictions. Different PDF readers respond differently to various combinations of options. Sometimes a PDF viewer may show you restrictions that differ from what you selected. This is probably not a bug in qpdf.

Options for 40-bit only:
--annotate=[y|n] restrict comments, filling forms, and signing
--extract=[y|n] restrict text/graphic extraction
--modify=[y|n] restrict document modification
--print=[y|n] restrict printing

Options for 128-bit or 256-bit:
--accessibility=[y|n] restrict accessibility (usually ignored)
--annotate=[y|n] restrict commenting/filling form fields
--assemble=[y|n] restrict document assembly
--extract=[y|n] restrict text/graphic extraction
--form=[y|n] restrict filling form fields
--modify-other=[y|n] restrict other modifications
--modify=modify-opt control modify access by level
--print=print-opt control printing access
--cleartext-metadata prevent encryption of metadata

For 128-bit only:
--use-aes=[y|n] indicates whether to use AES encryption
--force-V4 forces use of V=4 encryption handler

For 256-bit only:
--force-R5 forces use of deprecated R=5 encryption
--allow-insecure allow user password with empty owner password

Values for print-opt:
none disallow printing
low allow only low-resolution printing
full allow full printing

Values for modify-opt:
none allow no modifications
assembly allow document assembly only
form assembly + filling in form fields and signing
annotate form + commenting and modifying forms
all allow full document modification

Related Options:

--user-password=user-password

Set the user password of the encrypted file.

--owner-password=owner-password

Set the owner password of the encrypted file.

--bits={48|128|256}

Specify the encryption key length. For best security, always use a key length of 256.

--accessibility=[y|n]

This option is ignored except with very old encryption formats. The current PDF specification does not allow restriction of document accessibility. This option is not available with 40-bit encryption.

--annotate=[y|n]

Enable/disable modifying annotations including making comments and filling in form fields. For 128-bit and 256-bit encryption, this also enables editing, creating, and deleting form fields unless --modify-other=n or --modify=none is also specified.

--assemble=[y|n]

Enable/disable document assembly (rotation and reordering of pages). This option is not available with 40-bit encryption.

--extract=[y|n]

Enable/disable text/graphic extraction for purposes other than accessibility.

--form=[y|n]

Enable/disable whether filling form fields is allowed even if modification of annotations is disabled. This option is not available with 40-bit encryption.

--modify-other=[y|n]

Enable/disable modifications not controlled by --assemble, --annotate, or --form. --modify-other=n is implied by any of the other --modify options. This option is not available with 40-bit encryption.

--modify=modify-opt

For 40-bit files, modify-opt may only be y or n and controls all aspects of document modification.

For 128-bit and 256-bit encryption, modify-opt values allow enabling and disabling levels of restriction in a manner similar to how some PDF creation tools do it. modify-opt values map to other combinations of options as follows:

all: allow full modification (the default) annotate: --modify-other=n form: --modify-other=n --annotate=n assembly: --modify-other=n --annotate=n --form=n none: --modify-other=n --annotate=n --form=n --assemble=n

--print=print-opt

Control what kind of printing is allowed. For 40-bit encryption, print-opt may only be y or n and enables or disables all printing. For 128-bit and 256-bit encryption, print-opt may have the following values:

none: disallow printing low: allow low-resolution printing only full: allow full printing (the default)

If specified, don't encrypt document metadata even when encrypting the rest of the document. This option is not available with 40-bit encryption.
--use-aes=[y|n]

Enables/disables use of the more secure AES encryption with 128-bit encryption. Specifying --use-aes=y forces the PDF version to be at least 1.6. This option is only available with 128-bit encryption. The default is "n" for compatibility reasons. Use 256-bit encryption instead.

Allow creation of PDF files with empty owner passwords and non-empty user passwords when using 256-bit encryption.
This option is for testing and is never needed in practice since qpdf does this automatically when needed.
Use an undocumented, unsupported, deprecated encryption algorithm that existed only in Acrobat version IX. This option should not be used except for compatibility testing.

PAGE-SELECTION (select pages from one or more files)

Use the --pages option to select pages from multiple files. Usage:

qpdf in.pdf --pages --file=input-file [--range=page-range] [--password=password] [...] -- out.pdf

OR

qpdf in.pdf --pages input-file [--password=password] [page-range] [...] -- out.pdf

Between --pages and the -- that terminates pages option, repeat the following:

--file=filename [--range=page-range] [--password=password] [options]

For compatibility, the file and range can be specified positionally. qpdf versions prior to 11.9.0 require --password=password to immediately follow the filename. In the older syntax, repeat the following:

filename [--password=password] [page-range]

Document-level information, such as outlines, tags, etc., is taken from in.pdf and is preserved in out.pdf. You can use --empty in place of an input file to start from an empty file and just copy pages equally from all files. You can use "." as a shorthand for the primary input file (if not --empty). In the above example, "." would refer to in.pdf.

Use --password=password to specify the password for a password-protected input file. If the same input file is used more than once, you only need to supply the password the first time. If the page range is omitted, all pages are selected.

Run qpdf --help=page-ranges for help with page ranges.

Use --collate=n to cause pages to be collated in groups of n pages (default 1) instead of concatenating the input. Use --collate=i,j,k,... to take i from the first, then j from the second, then k from the third, then i from the first, etc.

Examples:

•
Start with in.pdf and append all pages from a.pdf and the even pages from b.pdf, and write the output to out.pdf. Document-level information from in.pdf is retained. Note the use of "." to refer to in.pdf.


qpdf in.pdf --pages . a.pdf b.pdf 1-z:even -- out.pdf

•
Take all the pages from a.pdf, all the pages from b.pdf in reverse, and only pages 3 and 6 from c.pdf and write the result to out.pdf. Use password "x" to open b.pdf:


qpdf --empty --pages a.pdf b.pdf --password=x z-1 c.pdf 3,6

More examples are in the manual.

OVERLAY-UNDERLAY (overlay/underlay pages from other files)

These options allow pages from another file to be overlaid or underlaid on the primary output. Overlaid pages are drawn on top of the destination page and may obscure the page. Underlaid pages are drawn below the destination page. Usage:

{--overlay|--underlay} [--file=]file
[--password=password]
[--to=page-range]
[--from=[page-range]]
[--repeat=page-range]
--

Note the use of "--" by itself to terminate overlay/underlay options.

For overlay and underlay, a file and optional password are specified, along with a series of optional page ranges. The default behavior is that each page of the overlay or underlay file is imposed on the corresponding page of the primary output until it runs out of pages, and any extra pages are ignored. You can also give a page range with --repeat to cause those pages to be repeated after the original pages are exhausted.

This options are repeatable. Pages will be stacked in order of appearance: first underlays, then the original page, then overlays.

Run qpdf --help=page-ranges for help with page ranges.

Related Options:

--to=page-range

Specify the range of pages in the primary output to apply overlay/underlay to. See qpdf --help=page-ranges for help with the page range syntax.

--from=[page-range]

Specify pages from the overlay/underlay file that are applied to the destination pages. See qpdf --help=page-ranges for help with the page range syntax. The page range may be omitted if --repeat is used.

--repeat=page-range

Specify pages from the overlay/underlay that are repeated after "from" pages have been exhausted. See qpdf --help=page-ranges for help with the page range syntax.

ATTACHMENTS (work with embedded files)

It is possible to list, add, or delete embedded files (also known as attachments) and to copy attachments from other files. See help on individual options for details. Run qpdf --help=add-attachment for additional details about adding attachments. See also --help=--list-attachments and --help=--show-attachment.

Related Options:

--add-attachment file [options] --

The --add-attachment flag and its options may be repeated to add multiple attachments. Run qpdf --help=add-attachment for details.

--copy-attachments-from file [options] --

The --copy-attachments-from flag and its options may be repeated to copy attachments from multiple files. Run qpdf --help=copy-attachments for details.

--remove-attachment=key

Remove an embedded file using its key. Get the key with --list-attachments.

PDF-DATES (PDF date format)

When a date is required, the date should conform to the PDF date format specification, which is "D:yyyymmddhhmmssz" where "z" is either literally upper case "Z" for UTC or a timezone offset in the form "-hh'mm'" or "+hh'mm'". Negative timezone offsets indicate time before UTC. Positive offsets indicate how far after. For example, US Eastern Standard Time (America/New_York) is "-05'00'", and Indian Standard Time (Asia/Calcutta) is "+05'30'".

Examples:

•
D:20210207161528-05'00' February 7, 2021 at 4:15:28 p.m.
•
D:20210207211528Z February 7, 2021 at 21:15:28 UTC

ADD-ATTACHMENT (attach (embed) files)

The options listed below appear between --add-attachment and its terminating "--".

Related Options:

--key=key

Specify the key to use for the attachment in the embedded files table. It defaults to the last element (basename) of the attached file's filename.

--filename=name

Specify the filename to be used for the attachment. This is what is usually displayed to the user and is the name most graphical PDF viewers will use when saving a file. It defaults to the last element (basename) of the attached file's filename.

--creationdate=date

Specify the attachment's creation date in PDF format; defaults to the current time. Run qpdf --help=pdf-dates for information about the date format.

--moddate=date

Specify the attachment's modification date in PDF format; defaults to the current time. Run qpdf --help=pdf-dates for information about the date format.

--mimetype=type/subtype

Specify the mime type for the attachment, such as text/plain, application/pdf, image/png, etc.

--description="text"

Supply descriptive text for the attachment, displayed by some PDF viewers.

Indicate that any existing attachment with the same key should be replaced by the new attachment. Otherwise, qpdf gives an error if an attachment with that key is already present.

COPY-ATTACHMENTS (copy attachments from another file)

The options listed below appear between --copy-attachments-from and its terminating "--".

To copy attachments from a password-protected file, use the --password option after the file name.

Related Options:

--prefix=prefix

Prepend a prefix to each key; may be needed if there are duplicate attachment keys. This affects the key only, not the file name.

INSPECTION (inspect PDF files)

These options provide tools for inspecting PDF files. When any of the options in this section are specified, no output file may be given.

Related Options:

Silently exit with a code indicating the file's encryption status:

0: the file is encrypted 1: not used 2: the file is not encrypted

This can be used with password-protected files even if you don't know the password.

Silently exit with a code indicating the file's password status:

0: a password, other than as supplied, is required 1: not used 2: the file is not encrypted 3: the file is encrypted, and correct password (if any) has been supplied

Check the structure of the PDF file as well as a number of other aspects of the file, and write information about the file to standard output. Note that qpdf does not perform any validation of the actual PDF page content or semantic correctness of the PDF file. It merely checks that the PDF file is syntactically valid. See also qpdf --help=exit-status.
Show document encryption parameters. Also show the document's user password if the owner password is given and the file was encrypted using older encryption formats that allow user password recovery.
When used with --show-encryption or --check, causes the underlying encryption key to be displayed.
Check to see whether a file is linearized and, if so, whether the linearization hint tables are correct.
Check and display all data in the linearization hint tables.
Show the contents of the cross-reference table or stream (object locations in the file) in a human-readable form. This is especially useful for files with cross-reference streams, which are stored in a binary format.
--show-object={trailer|obj[,gen]}

Show the contents of the given object. This is especially useful for inspecting objects that are inside of object streams (also known as "compressed objects").

When used with --show-object, if the object is a stream, write the raw (compressed) binary stream data to standard output instead of the object's contents. See also --filtered-stream-data.
When used with --show-object, if the object is a stream, write the filtered (uncompressed, potentially binary) stream data to standard output instead of the object's contents. See also --raw-stream-data.
Print the number of pages in the input file on a line by itself. Useful for scripts.
Show the object and generation number for each page dictionary object and for each content stream associated with the page.
When used with --show-pages, also shows the object and generation numbers for the image objects on each page.
Show the key and stream number for each embedded file. Combine with --verbose for more detailed information.
--show-attachment=key

Write the contents of the specified attachment to standard output as binary data. Get the key with --list-attachments.

JSON (JSON output for PDF information)

Show information about the PDF file in JSON format. Please see the JSON chapter in the qpdf manual for details.

Related Options:

--json[=version]

Generate a JSON representation of the file. This is described in depth in the JSON section of the manual. "version" may be a specific version or "latest" (the default). Run qpdf --json-help for a description of the generated JSON object.

--json-help[=version]

Describe the format of the JSON output by writing to standard output a JSON object with the same keys and with values containing descriptive text.

--json-key=key

This option is repeatable. If given, only the specified top-level keys will be included in the JSON output. Otherwise, all keys will be included. With --json-output, when not given, only the "qpdf" key will appear in the output.

--json-object={trailer|obj[,gen]}

This option is repeatable. If given, only specified objects will be shown in the "objects" key of the JSON output. Otherwise, all objects will be shown.

--json-stream-data={none|inline|file}

When used with --json, this option controls whether streams in json output should be omitted, written inline (base64-encoded) or written to a file. If "file" is chosen, the file will be the name of the output file appended with -nnn where nnn is the object number. The prefix can be overridden with --json-stream-prefix. The default is "none", except when --json-output is specified, in which case the default is "inline".

--json-stream-prefix=file-prefix

When used with --json-stream-data=file, --json-stream-data=file-prefix sets the prefix for stream data files, overriding the default, which is to use the output file name. Whatever is given here will be appended with -nnn to create the name of the file that will contain the data for the stream stream in object nnn.

--json-output[=version]

Implies --json=version. Changes default values for certain options so that the JSON output written is the most faithful representation of the original PDF and contains no additional JSON keys. See also --json-stream-data, --json-stream-prefix, and --decode-level.

Treat the input file as a JSON file in qpdf JSON format. See the "qpdf JSON Format" section of the manual for information about how to use this option.
--update-from-json=qpdf-json-file

Update a PDF file from a JSON file. Please see the "qpdf JSON" chapter of the manual for information about how to use this option.

TESTING (options for testing or debugging)

The options below are useful when writing automated test code that includes files created by qpdf or when testing qpdf itself.

Related Options:

Use a fixed value for the document ID. This is intended for testing only. Never use it for production files. See also qpdf --help=--deterministic-id.
Use a static initialization vector for AES-CBC. This is intended for testing only so that output files can be reproducible. Never use it for production files. This option is not secure since it significantly weakens the encryption.
--linearize-pass1=file

Write the first pass of linearization to the named file. The resulting file is not a valid PDF file. This option is useful only for debugging qpdf.

This is used by qpdf's test suite to check consistency between the output of qpdf --json and the output of qpdf --json-help.
This is used by qpdf's performance test suite to report the maximum amount of memory used in supported environments.

SEE ALSO

For a summary of qpdf's options, please run qpdf --help. A complete manual can be found at https://qpdf.readthedocs.io.

qpdf version 11.9.0