qpdf

TLDR

Decrypt PDF

$ qpdf --decrypt [input.pdf] [output.pdf]

Linearize PDF (optimize for web)

$ qpdf --linearize [input.pdf] [output.pdf]

Merge PDFs

$ qpdf --empty --pages [file1.pdf] [file2.pdf] -- [output.pdf]

Extract specific pages

$ qpdf --empty --pages [input.pdf] [1-5,10] -- [output.pdf]

Rotate pages

$ qpdf [input.pdf] [output.pdf] --rotate=[+90:1-5]

Compress streams

$ qpdf --compress-streams=y [input.pdf] [output.pdf]

Check PDF structure

$ qpdf --check [input.pdf]

Remove password

$ qpdf --password=[pass] --decrypt [encrypted.pdf] [output.pdf]

SYNOPSIS

qpdf [--decrypt] [--linearize] [--pages spec] [--rotate spec] [options] input output

qpdf is a command-line tool for structural, content-preserving transformations of PDF files. Unlike tools that rasterize or re-render, qpdf manipulates PDF structure directly.
Primary uses include encryption management (decrypting, encrypting, changing passwords), linearization (optimizing for web delivery), and page manipulation (merging, splitting, reordering).
Page specification uses flexible syntax: ranges (1-10), specific pages (1,3,5), reverse (z-1), and rotation (1-5:90). Multiple files can contribute pages using --pages with file:range pairs.
The --check option validates PDF structure without modifying, useful for identifying damaged files. JSON output exposes internal structure for analysis or custom processing.
QDF mode produces "normalized" PDFs that can be edited with text editors, enabling debugging and manual fixes. Stream decompression reveals human-readable content.
Linearization reorganizes PDFs for efficient byte-serving over HTTP, enabling page-at-a-time loading without downloading entire files.

PARAMETERS

--decrypt

Remove encryption.

--linearize

Optimize for web viewing.

--encrypt user owner bits

Add encryption.

--pages spec

Page selection specification.

--rotate [+|-]angle:pages

Rotate pages.

--empty

Use empty PDF as input base.

--check

Check PDF structure.

--show-encryption

Display encryption details.

--password PASS

Input file password.

--compress-streams[=y|n]

Compress/decompress streams.

--decode-level LEVEL

Stream decoding: none, generalized, specialized, all.

--normalize-content[=y|n]

Normalize content streams.

--split-pages[=n]

Split into n-page files.

--overlay file

Overlay pages from file.

--underlay file

Underlay pages from file.

--flatten-rotation

Make rotation permanent.

--flatten-annotations

Flatten annotation appearances.

--json

Output PDF structure as JSON.

--qdf

Create QDF (editable PDF source).

CAVEATS

Cannot edit text content (use other tools). Password-protected files need password for processing. Some malformed PDFs may not process. Large PDFs require significant memory. Encryption strength limited by PDF specification.

HISTORY

qpdf was created by Jay Berkenbilt at Apex CoVantage starting around 2005. Originally internal tooling for PDF processing, it was open-sourced and has become a standard library and command-line tool. Unlike PDF editors, qpdf focuses on structural transformations that preserve content exactly.