How to Merge PDF Files on Linux

Sometimes, you may have 2 or more PDF files that you need to combine or merge into one so that you can have everything in one place. This will minimize time wasted trying to look for your PDF files which may be in different folders and other directories.

Recently I have tested a few tools to merge pdf files on Linux that I will introduce to you today.  I have tested all the tools on the Ubuntu 18.04 version.

1) Using pdfunite

Pdfunite is a handy tool that can be used for merging to or more PDF documents. It is part of poppler-utils package, so when you install poppler utils, you end up with pdfunite.

To install pdfunite, we’ll install the poppler-utils package as shown

apt install poppler-utils

Sample Output

Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
  fontconfig-config fonts-dejavu-core libcairo2 libfontconfig1 liblcms2-2 libpixman-1-0 libpoppler58
  libxcb-render0 libxcb-shm0 libxrender1
Suggested packages:
  liblcms2-utils poppler-data
The following NEW packages will be installed:
  fontconfig-config fonts-dejavu-core libcairo2 libfontconfig1 liblcms2-2 libpixman-1-0 libpoppler58
  libxcb-render0 libxcb-shm0 libxrender1 poppler-utils

Next. update the system

apt update

In the downloads folder, I have 2 PDF documents

  1. linux_for_beginners.pdf
  2. linux_for_beginners_2.pdf

How to merge PDF documents in Ubuntu 18.04

We are going to merge them using pdfunite command.

To merge the PDF documents, the syntax will be as shown

pdfunite file1.pdf file2.pdf merged_output.pdf

Using our files as shown earlier, the command will be

pdfunite linux_for_beginners.pdf linux_for_beginners_2.pdf merged_output.pdf

You will get the following warning in the output, but don’t worry. The files have already been merged.

merge PDF documents in Ubuntu 18.04

As you can see, the output file merged_output.pdf has been created

merge PDF documents in Ubuntu 18.04

Note: Files to be merged need to be in the same directory where pdfunife is executed

2) Using pdftk tool

Pdftk is yet another tool that can be used to merge PDF documents in Ubuntu 18.04. To install pdftk on terminal in Ubuntu 18.04, first add the pdftk repository

add-apt-repository ppa:malteworld/ppa

Output

More info: https://launchpad.net/~malteworld/+archive/ubuntu/ppa
Press [ENTER] to continue or Ctrl-c to cancel adding it.

Hit:1 http://repo.mysql.com/apt/ubuntu bionic InRelease
Get:2 http://security.ubuntu.com/ubuntu bionic-security InRelease [83.2 kB]
Hit:3 http://ke.archive.ubuntu.com/ubuntu bionic InRelease
Get:4 http://ke.archive.ubuntu.com/ubuntu bionic-updates InRelease [88.7 kB]
Hit:5 http://ppa.launchpad.net/dawidd0811/neofetch/ubuntu bionic InRelease
Hit:6 http://linux.teamviewer.com/deb stable InRelease
Get:7 http://ppa.launchpad.net/malteworld/ppa/ubuntu bionic InRelease [15.3 kB]
Hit:8 http://linux.teamviewer.com/deb preview InRelease
Get:9 http://ke.archive.ubuntu.com/ubuntu bionic-backports InRelease [74.6 kB]
Hit:10 http://ppa.launchpad.net/webupd8team/java/ubuntu bionic InRelease

Next, update your Ubuntu System

 apt update

After successfully updating your system, install the pdftk tool as shown below

apt install pdftk

After the installation of pdftk is complete, you can now invoke the pdftk command to merge files. The syntax is as shown

pdftk file1.pdf file2.pdf  cat output merged_output.pdf

using our earlier files, the command will be as shown

pdftk Linux_for_beginners.pdf Linux_for_beginners_2.pdf cat output merged_output.pdf

merge PDF documents in Ubuntu 18.04

3) Using Convert tool

To use the convert command, first install it on terminal using the command below

apt install imagemagick

Output

The following packages will be upgraded:
  imagemagick
1 upgraded, 0 newly installed, 0 to remove and 494 not upgraded.
Need to get 14.2 kB of archives.
After this operation, 0 B of additional disk space will be used.
Get:1 http://ke.archive.ubuntu.com/ubuntu bionic-updates/main amd64 imagemagick amd64 8:6.9.7.4+dfsg-16ubuntu6.3 [14.2 kB]
Fetched 14.2 kB in 2s (8,300 B/s)
(Reading database ... 142831 files and directories currently installed.)
Preparing to unpack .../imagemagick_8%3a6.9.7.4+dfsg-16ubuntu6.3_amd64.deb ...
Unpacking imagemagick (8:6.9.7.4+dfsg-16ubuntu6.3) over (8:6.9.7.4+dfsg-16ubuntu5) ...
Setting up imagemagick (8:6.9.7.4+dfsg-16ubuntu6.3) ...

Upon successful installation, you can now merge your documents.

The syntax for merging 2 PDF files is as shown

convert file1.pdf file2.pdf merged_output.pdf

Using our files , the command will be

convert Linux_for_beginners.pdf Linux_for_beginners_2.pdf output.pdf

Output

merge PDF documents in Ubuntu 18.04

To Merge specific PDF pages into a single PDF file, you'll need to pass our files with specific page numbers in square brackets to the convert command. For example to merge the 5th page from the first document with 7th and 10th pages in the second document, the syntax will be

convert file1.pdf[4] file2.pdf[6,9] merged_pages.pdf

Using our files , the command will be

convert Linux_for_beginners.pdf[4] Linux_for_beginners_2.pdf[6,9] merged_pages.pdf

Output

merge PDF documents in Ubuntu 18.04

And Yes, it's very possible to join page ranges.

For Example, you can join the first 5 pages from first file with first 10 pages from the other file. The syntax for this case will be

convert file1.pdf[0-4] file2.pdf[0-9] merged_page_ranges.pdf

Using our files , the command will be

convert Linux_for_beginners.pdf[0-4] Linux_for_beginners_2.pdf[0,9] merged_page_ranges.pdf

merge PDF documents in Ubuntu 18.04

4) Using Ghostscript

We can also use ghostscript (gs) to merge PDf documents in Ubuntu 18.04
apt install ghostscript

Example of using ghostscript to merge 2 PDF documents

gs -dNOPAUSE -sDEVICE=pdfwrite -sOUTPUTFILE=combine.pdf -dBATCH file1.pdf file2.pdf

In the above example, let's expound further on the attributes

-sOUTPUTFILE denotes the output file

-dBATCH denotes the pdf documents to be merged

Using our documents earlier, the command will be

gs -dNOPAUSE -sDEVICE=pdfwrite -sOUTPUTFILE=combine.pdf -dBATCH Linux_for_beginners.pdf Linux_for_beginners_2.pdf

Sample Output

GPL Ghostscript 9.22 (2017-10-04)
Copyright (C) 2017 Artifex Software, Inc.  All rights reserved.
This software comes with NO WARRANTY: see the file PUBLIC for details.
Processing pages 1 through 29.
Page 1
Page 2
Loading NimbusSans-Regular font from /usr/share/ghostscript/9.22/Resource/Font/NimbusSans-Regular... 5056280 3684544 3235592 1819445 3 done.
Page 3
Page 4
Page 5
Page 6
Page 7
Page 8

5) Using pdfsam

Pdfsam is a simple, intuitive and easy to use GUI tool that is used to merge, split, rotate, edit and sign PDF documents. In this example, we are going to use the tool to merge PDF documents in Ubuntu 18.04. But first, let's install it

apt install openjdk-8-jre libopenjfx-jni libopenjfx-java openjfx

After successful installation, define the JAVA_HOME variable in /etc/environment path using your favorite editor.

nano /etc/environment

Append the following line.

JAVA_HOME="/usr/lib/jvm/java-8-openjdk-amd64/"

Save and Exit

reload the file

source /etc/environment

Next, download the Debian package file from pdfsam's official site

wget https://github.com/torakiki/pdfsam/releases/download/v3.3.6/pdfsam_3.3.6-1_all.deb

Once downloaded, install the deb file using the dpkg command as shown.

dpkg -i pdfsam_3.3.6-1_all.deb

Sample Output

(Reading database ... 146399 files and directories currently installed.)
Preparing to unpack pdfsam_3.3.6-1_all.deb ...
Unpacking pdfsam-basic (3.3.6-1) over (3.3.6-1) ...
Setting up pdfsam-basic (3.3.6-1) ...
Processing triggers for gnome-menus (3.13.3-9) ...
Processing triggers for desktop-file-utils (0.23-1) ...
Processing triggers for mime-support (3.60) ...

To start pdfsam, run

pdfsam

merge PDF documents in Ubuntu 18.04

To merge documents, click on 'Merge' and drag and drop the files to be merged in the section provided.

merge PDF documents in Ubuntu 18.04

Feel free to specify other attributes in the 'Merge Settings' section and once done click on the 'Run' icon located at the bottom. Once done, you'll hear a 'ding' sound notifying you that the merging process is complete.

merge PDF documents in Ubuntu 18.04

As seen in the above examples, merging PDF files on Linux is very easy and straight forward on the terminal. Give it a try and let us know how it went. Your Feedback is much welcome in our comment section. Thank you and feel free to share this tutorial on your social handles.

Winnie Ondara 8:06 am

About Winnie Ondara

I’m Winnie, a passionate Linux administrator and an open source enthusiast. I enjoy keeping myself up to date with the latest in the Linux world and trying out the latest tools, features and services in the FOSS community.

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