gabeujin/pdftk-server

PDFtk Server

PDFtk Server is a command-line tool for working with PDF documents. It can merge, split, rotate, encrypt, decrypt, watermark, stamp, fill forms, extract metadata, and manipulate PDFs in a variety of ways.

When to Use This Skill

• Merging or joining multiple PDF files into one
• Splitting or bursting a PDF into individual pages
• Rotating PDF pages
• Encrypting or decrypting PDF files
• Filling PDF form fields from FDF/XFDF data
• Applying background watermarks or foreground stamps
• Extracting PDF metadata, bookmarks, or form field information
• Repairing corrupted PDF files
• Attaching or extracting files embedded in PDFs
• Removing specific pages from a PDF
• Collating separately scanned even/odd pages
• Compressing or decompressing PDF page streams

Prerequisites

• PDFtk Server must be installed on the system
  • Windows: winget install --id PDFLabs.PDFtk.Server
  • macOS: brew install pdftk-java
  • Linux (Debian/Ubuntu): sudo apt-get install pdftk
  • Linux (Red Hat/Fedora): sudo dnf install pdftk
• Access to a terminal or command prompt
• Verify installation by running pdftk --version

Step-by-Step Workflows

Merge Multiple PDFs

pdftk file1.pdf file2.pdf cat output merged.pdf

Using handles for more control:

pdftk A=file1.pdf B=file2.pdf cat A B output merged.pdf

Split a PDF into Individual Pages

pdftk input.pdf burst

Extract Specific Pages

Extract pages 1-5 and 10-15:

pdftk input.pdf cat 1-5 10-15 output extracted.pdf

Remove Specific Pages

Remove page 13:

pdftk input.pdf cat 1-12 14-end output output.pdf

Rotate Pages

Rotate all pages 90 degrees clockwise:

pdftk input.pdf cat 1-endeast output rotated.pdf

Encrypt a PDF

Set an owner password and a user password with 128-bit encryption (default):

pdftk input.pdf output secured.pdf owner_pw mypassword user_pw userpass

Decrypt a PDF

Remove encryption using the known password:

pdftk secured.pdf input_pw mypassword output unsecured.pdf

Fill a PDF Form

Populate form fields from an FDF file and flatten to prevent further edits:

pdftk form.pdf fill_form data.fdf output filled.pdf flatten

Apply a Background Watermark

Place a single-page PDF behind every page of the input (input should have transparency):

pdftk input.pdf background watermark.pdf output watermarked.pdf

Stamp an Overlay

Place a single-page PDF on top of every page of the input:

pdftk input.pdf stamp overlay.pdf output stamped.pdf

Extract Metadata

Export bookmarks, page metrics, and document information:

pdftk input.pdf dump_data output metadata.txt

Repair a Corrupted PDF

Pass a broken PDF through pdftk to attempt automatic repair:

pdftk broken.pdf output fixed.pdf

Collate Scanned Pages

Interleave separately scanned even and odd pages:

pdftk A=even.pdf B=odd.pdf shuffle A B output collated.pdf

Troubleshooting

| Issue | Solution | |-------|----------| | pdftk command not found | Verify installation; check that pdftk is in your system PATH | | Cannot decrypt PDF | Ensure you are providing the correct owner or user password via input_pw | | Output file is empty or corrupt | Check input file integrity; try running pdftk input.pdf output repaired.pdf first | | Form fields not visible after fill | Use the flatten flag to merge fields into the page content | | Watermark not appearing | Ensure the input PDF has transparent regions; use stamp for opaque overlays | | Permission denied errors | Check file permissions on input and output paths |

References

Bundled reference documents in the references/ folder:

• pdftk-man-page.md - Complete manual reference with all operations, options, and syntax
• pdftk-cli-examples.md - Practical command-line examples for common tasks
• download.md - Installation and download instructions for all platforms
• pdftk-server-license.md - PDFtk Server licensing information
• third-party-materials.md - Third-party library licenses