Why Compare PDFs?

Comparing PDFs saves time, reveals unexpected or unwelcome changes, and helps you avoid costly mistakes.

Authors & Publishers
If you produce PDFs for publication, a PDF comparison tool can show you the exact differences between, say, the first printing, and your proposed second printing. This way you can easily spot unintended changes to the pagination. Also, you can save time by checking only those pages that have changed, rather than having to review the whole publication all over again.
Journalists, Police, and Other Investigators
It is common to follow a paper trail of emails, memos, and so on, as part of an investigation. This trail will often include PDF documents. Using a PDF comparison tool will allow you to observe the evolution of a document—perhaps revealing when critical changes were made.
Legal Professionals, Legislators, & Freelancers
When a contract, legislation, or other legal document is being drawn up, how can you be sure that the changes made are correct, and are only those agreed? By using a PDF comparison tool you can see exactly what has changed between the latest draft and any previous draft.
As reports and other documents are developed they go through many changes. If your company process uses PDFs, using a PDF comparison tool will show you how each new version differs from its predecessor. This saves you having to reread everything, and makes it much easier to see what changes you want to comment on or change.
Software Testers & Quality Assurance Engineers
Many business processes produce PDFs as an output. Using a PDF comparison tool makes it easy to verify that the PDFs are being produced correctly, or to spot exactly where any mistakes have occurred.

The DiffPDF application makes it easy for anyone to compare PDF files: simply choose the first PDF, then the second PDF, and then click the Compare button. The changes are shown visually, as if you'd used highlighter pens to show added, changed, or deleted text.

The diffpdfc tool is for technical users. It is a command line tool that can be used in batch files, C# programs, Visual Basic scripts, and so on, to be integrated into quality assurance or software testing processes.

Both tools are mature and well-established. They have been successfully used in all the roles described above—and many others—for several years. They are in use in over forty-five countries throughout the world. They are widely used in the financial sector (especially by banks and insurance companies), as well as by many Government departments.

Each product is normally sold and licensed separately; however, our site licenses cover all our PDF comparison products.