In the world where we are increasingly trying to avoid using paper, simple yet capable file formats like PDF reigns supreme. Viewing and creating PDF files is as easy as sending them, but editing a PDF is another story.
PDF files are notoriously hard to edit. Part of the reason is the popular format is made by Adobe in 1993 as a presentation format, which focus on displaying the same document across different platform. But over the years, people have developed ways to edit PDF, though not as flexible as if you're editing a Microsoft Word document.
This article will be a handy list of the most popular and feature-completed open source PDF editors. We will also cover some of their main features to serve as a reference, though you need to consult official websites and documentation pages for more detailed information.
LibreOffice is an open source office suite, compete directly against Microsoft Office. It consists of programs designed for word, spreadsheet and presentation slideshow processing, a graphical database interface, and so much more. LibreOffice is the most actively developed OpenOffice successor and runs on all major platforms including Windows, MacOS, Linux, Android, iOS and any operating system that supports web-based apps.
Being a part of LibreOffice, LibreOffice Draw is originally designed to handle graphics and diagrams the same way CorelDraw does. It also does a fantastic job of editing complex PDF files. Using LibreOffice Draw, you have access to the texts and images inside the PDFs and can freely edit or delete them the way you want.
Please do note that if your system does not have the font used in the file, it will be substituted with one of the fonts available. And you also need to OCR a scanned PDF file before you can directly edit the text inside it.
Inkscape is a popular open source vector graphics editor. While it's not exactly a PDF editor, it can render PDF elements and load it into its interface (using Poppler) where you would be able to re-arrange, edit or delete images and text objects.
Inkscape allows you to maintain the appearance the look and feel of the paragraphs inside PDF file without having to install the actual font. The only downside is you lose the text data once you save the document as they are converted to vector graphics (shapes of letter). That means you cannot select and copy text from the output file if you don't run it through an OCR software.
When handling large files without its fonts installed, Inkscape can be laggy and sometimes crash due to the large amount of graphics it has to process. But generally, it does what most people need when they look for an open source PDF editor.
PDFedit is a stand-alone library designed for manipulating PDF documents. It also includes graphical interface for Windows, Linux/Unix.
Under the surface, PDFedit leverages Xpdf library for low level PDF manipulation. It allows you to do a handful of operations on PDF files, including :
- Merge, join, split PDF files.
- Add, remove, change the colour, font size and font type of text.
- Revision control.
- Draw simple objects on top of the page, such as lines, rectangles, etc.
- Rotate a few pages or all the pages.
- Extract text from PDF files
- Manage layers inside each page.
- Mass processing through scripting the terminal interface
The software offers many low-level features for advanced users who have deep knowledge of PDF specifications. You can either edit raw PDF objects or create a script to process a batch of PDFs in the same way. Even better, PDFedit is extendable, you can code your own script or plugin to enhance the tool.
PDFedit is licensed with GNU GPL v2 and can be downloaded freely at its official website : pdfedit.cz
PDFtk - a low-level tool for manipulating PDF files
PDFtk (PDF Toolkit) is a cross-platform PDF editor. The software is released in three different version : PDFtk Server (open-source command-line tool), PDFtk Free (freeware, proprietary) and PDFtk Pro (proprietary paid).
Most of the processing are done through the command-line utility, so if you're a developer, you can code your own graphical interface to it.
PDFtk can extract and inject bookmark metadata, rearrange and concatenate pages, combine many PDFs into one, break a PDF apart, watermark pages, and much more. Please visit PDFtk homepage for more details
Xournal++ is an cross-platform, open source, hand note-taking software with the target of flexibility, functionality, and speed.
While the software is not exactly a PDF editor, it is capable of adding graphics and text on top of a PDF file, if that's what you're looking for. We think the feature is useful enough to be included in this list.
You can find more details about Xournal++ at https://xournalpp.github.io/