pdftk merge pdf

May 8, 2025 6 min read

Merging PDF documents is a common requirement for various tasks, ranging from compiling reports to combining scanned documents. Several tools and methods are available to achieve this, each with its strengths and weaknesses. In this article, we will explore how to merge PDFs using PDFtk, a powerful command-line tool, and introduce BreezePDF as a convenient and user-friendly alternative. BreezePDF simplifies PDF handling, offering an accessible solution for both basic and advanced PDF tasks. BreezePDF makes it easy to create PDFs for free that you or others can fill in.

Merge PDFs Effortlessly with BreezePDF!

Create and merge PDFs online easily, privately, and completely free without signing up or downloading software.

Merge PDFs with BreezePDF →

PDFtk is a robust tool known for its command-line interface, offering a wide range of PDF manipulation capabilities. However, it might be intimidating for users unfamiliar with command-line environments. BreezePDF offers an intuitive graphical interface, making PDF merging and other tasks straightforward for users of all technical levels. This article aims to provide a comprehensive guide on using both PDFtk and BreezePDF to merge PDFs, allowing users to choose the method that best suits their needs and preferences.

What is PDFtk?

PDFtk, short for PDF Toolkit, is a versatile and lightweight utility designed for everyday PDF manipulation tasks. It's a simple tool for everyday PDF tasks. Its primary function is to simplify common PDF operations, such as merging, splitting, rotating, and stamping PDF documents. PDFtk comes in different flavors, including PDFtk Free (a GUI-based version), PDFtk Pro (also GUI-based with advanced features), and PDFtk Server (a command-line tool).

When it comes to merging PDFs, PDFtk offers straightforward functionality through its command-line interface. Beyond merging, PDFtk boasts other functions like splitting, rotating, stamping, and more, however, the focus here is on merging. This makes it a valuable tool for users who require efficient and precise control over their PDF documents. PDFtk is a valuable tool, especially for those comfortable with command-line operations, but BreezePDF might be a better option for users of all technical levels to create fillable PDFs.

PDFtk has been around for around 20 years as a server-side processing tool, offering reliable PDF manipulation capabilities for many years. It was created by Sid Steward, who authored the PDF Hacks book, reflecting his expertise in PDF technology. The tool's longevity and widespread adoption are testaments to its utility and effectiveness in handling various PDF-related tasks.

Installing PDFtk

Installing PDFtk depends on your operating system. On Windows, users can download the PDFtk Free or Pro installer from the PDF Labs website. The installation process is typically straightforward, involving downloading the installer and following the on-screen prompts.

For Linux users, specifically on Ubuntu/Debian distributions, PDFtk can be installed using the `sudo snap install pdftk` command. Alternatively, you can use `sudo apt install pdftk-java` on Ubuntu 20.04 LTS. It's important to note that the apt installation might be buggy, as noted on bugs.launchpad.net/ubuntu/+source/pdftk/+bug/779908, so caution is advised. If PDFtk is unavailable or problematic, alternative tools like PDFSam, QPDF, jPDFTweak, pdfsam or pdfjam can be considered.

How to Merge PDFs Using PDFtk (Command Line)

Merging PDFs with PDFtk involves using specific commands in the command line. The basic command to merge two PDF files is `pdftk file1.pdf file2.pdf cat output mergedfile.pdf`. This command takes `file1.pdf` and `file2.pdf` as input, uses the `cat` command to concatenate them, and outputs the merged result to `mergedfile.pdf`. Understanding this command is crucial for utilizing PDFtk's merging capabilities effectively.

To make the command more readable and manageable, you can use handles. For example, the command `pdftk A=file1.pdf B=file2.pdf cat A B output mergedfile.pdf` assigns the handle `A` to `file1.pdf` and `B` to `file2.pdf`, making it easier to reference the files. This method is particularly useful when dealing with multiple files, as it simplifies the command structure and reduces the risk of errors.

PDFtk also supports the use of wildcards for merging multiple PDFs in a directory. The command `pdftk *.pdf cat output combined.pdf` merges all PDF files in the current directory into a single file named `combined.pdf`. This approach streamlines the merging process when dealing with a large number of files in a single directory. Specify a range of files with `pdftk in.pdf cat 1-12 14-end output out1.pdf`

When working with PDFtk, it's essential to be aware of potential issues. File order matters, as PDFtk merges files in the order they are listed in the command. In Linux, you can control the file system output sequence using `pdftk $(ls -v *.pdf) cat output merged.pdf`. Password-protected PDFs require handling password prompts appropriately. Use qpdf to handle problems where pdftk can't by installing with `sudo apt install qpdf` then running `qpdf --empty --pages in1.pdf in2.pdf in3.pdf -- out.pdf`. To avoid overwriting existing files, ensure the output file has a unique name. When merging with different page sizes, use convert -page a4 image.jpg page2.pdf or pdfjam --outfile out.pdf --paper a4paper in.pdf.

Alternative Tools for Merging PDFs

While PDFtk is a powerful tool, several alternative tools offer similar PDF merging capabilities. PDF Arranger (formerly PDF-Shuffler) is a GUI-based tool for merging, rearranging, and deleting pages, install with `sudo apt install pdfarranger`. Pdfunite (Poppler Utils) is a simple command-line tool, install with `sudo apt-get install poppler-utils` and run with `pdfunite in-1.pdf in-2.pdf in-n.pdf out.pdf`. Ghostscript is a versatile tool for various PDF manipulations using `gs -dBATCH -dNOPAUSE -q -sDEVICE=pdfwrite -dAutoRotatePages=/None -sOutputFile=finished.pdf file1.pdf file2.pdf`.

Other tools include PDF Chain (a GUI front-end for PDFtk), PDFMod (a GUI PDF editor), and pdfsam (a GUI tool for splitting and merging PDFs), install with `sudo apt install pdfsam`. LaTeX provides an alternative approach using LaTeX and the `pdfpages` package, but may break hyperlinks. Each of these tools provides different interfaces and capabilities, catering to various user preferences and requirements.

Streamlined PDF Merging with BreezePDF

BreezePDF offers a streamlined approach to PDF merging, providing a user-friendly graphical interface. Unlike command-line tools like PDFtk, BreezePDF simplifies the merging process, making it accessible to users of all technical levels. With BreezePDF, users can easily merge PDF documents with just a few clicks, eliminating the need to remember complex commands or navigate command-line environments.

The intuitive interface of BreezePDF enhances the merging experience, allowing users to quickly combine multiple PDF files into a single document. BreezePDF's drag-and-drop functionality makes it easy to reorder the merged PDFs. The features of BreezePDF further enhance the merging experience, providing a seamless and efficient way to manage your PDF documents. BreezePDF allows you to add fillable form fields too.

Conclusion

In summary, PDFtk is a useful tool for merging PDFs, especially for users comfortable with command-line interfaces. It offers precise control over the merging process and provides a range of advanced features. However, for users seeking a more accessible and efficient solution, BreezePDF offers a user-friendly alternative with its intuitive graphical interface. All the magic happens in your browser!

BreezePDF makes PDF merging and other PDF tasks easy and straightforward, with a range of features designed to enhance the user experience. Embrace the simplicity and efficiency of BreezePDF for all your PDF merging needs. We encourage you to try BreezePDF for easy PDF merging and experience the convenience firsthand.