PDiff How to compare PDF now 2083x faster and 100% error-free.

Compare PDF files with PDiff

Compare PDF contracts and legal texts with PDiff

You have two versions of a document and now you want to know: What are the differences, what has remained the same?

Are you tired of the tedious comparison by eyeballing?

Or do you already use a comparison tool, but are not satisfied with the results?

Then you are exactly right here. Read on why our software PDiff really helps you:

Why compare documents with PDiff (and not by eyeballing)?

Because you have better things to do. Not to mention the mistakes that can happen to the best reader every now and then.


Error-free and tireless, so you’ll never miss something again.

PDiff does the proofreading with care and with constant attention, even for completely changed layouts.

So you won’t overlook even the slightest text deviation: You won’t miss any legally or technically relevant difference. For sure.


Lightning fast and objective, so that the results are always the same no matter how much time is available or who the reader is.

Even for long documents, you have the results within a few seconds.

Differences are clearly and precisely documented on screen and in the proof report. The results are reproducible and objective. And can be used for internal and external communication.

Paper plane

Efficient, so you have more time to do what you really want.

With PDiff you see the differences at a glance. You can focus on what matters most: examining and reviewing your texts.

Compare PDF files with PDiff: Speed and precision for human versus PDiff

Performance comparison human versus PDiff. top: Speed in words per minute (WPM)1,2, bottom: Precision as percentage of detected word errors3.

Check out who compares PDFs faster: you or PDiff?
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How to compare PDF files with PDiff.

Drag two PDFs into the PDiff window and you will see all text differences in the unique synchronous display:

  • Insertions
  • Deletions
  • Replacements
  • Rearrenged text
  • optionally also style differences (fonts and attributes such as bold, italic, underline, strikethrough, superscripts and subscripts)

The comparison works even for different layouts. So even if fonts, hyphenation, column breaks or even page breaks have been changed.

PDiff shows all similarities and differences within a few seconds2.

Proofreading becomes seeing instead of searching.

The screencast shows you how fast you compare your PDF files with PDiff.

Simplified workflow. 1, 2, 3, done.

In the simplest case, the workflow with PDiff consists of the following steps:




1 2 3

In­sert in­puts

Re­view dif­fer­ences

Save re­sults

Details for the individual steps can be found in the following sections. Or directly by a click on the corresponding icon.


Typical workflow. Less is more.

In addition to the simplified workflow it is recommended that you carry out another important step before reviewing the differences:





1 2a 2b 3

In­sert in­puts

Sim­pli­fy dif­fer­ences

Re­view dif­fer­ences

Save re­sults

The aim of this step is to reduce the number of differences as much as possible, so that the relevant differences stand out clearly and you can focus your reviewing on these differences.

Automation. When things have to go even faster.

If you …

  • … want to compare a lot of documents
  • … have very large documents with longer computing times
  • … plan to integrate the document comparison into other software systems

then a fundamentally different workflow is possible:




You can automate PDiff – by batch processing in the GUI or via command line interface (CLI) without any GUI. For details, see the section Automation.

Try out how easy it is to compare your documents with PDiff.
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ImportJust right for your documents.

Applications of PDiff.

PDiff is an ideal solution to compare versions of your documents:

  • important office documents
  • mission critical technical manuals
  • legal texts and business contracts
  • pharmaceutical packaging and medical leaflets
  • financial reports
  • manuscripts and thesis texts
  • scientific articles, reports, and proceedings
  • fictional books and non-fiction books
  • price lists and catalogs
  • copywriting to press-ready layout

Compare two pdf files e.g. medical leaflets

Compare Word files (DOC/DOCX) with PDF.

PDiff provides an import mechanism for all common document formats: DOC/DOCX, RTF, TXT, XLS (Excel), etc.

Formats other than PDF are converted auto­matically by calling their native applications. So you can also compare Word files with PDF.

Checking foreign-language texts.

PDiff comes with full Unicode support. You can also easily compare texts in non-Roman writing systems: e.g. Chinese/Japanese /Korean (CJK), Arabic, Hebrew.

To highlight the differences between two documents, with PDiff you do not even have to speak the language yourself.

Test PDiff with your own documents.
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InspectSynchronized display of PDF and text.

To show you a clearly understandable comparison result of your documents, PDiff offers you a unique synchronous display and intuitive navigation tools:

  • See differences highlighted as colored markings in the PDFs and side-by-side in a tabular text synopsis.
  • With several tools you can directly navigate from difference to difference.
  • Different types of deviations can be inspected.
  • You can check off differences with an OK mark to mark changes that have been accepted or to hide less relevant changes.
  • Optionally, differences can also be supplemented with comments.

Try out the synchronized display directly in the web browser.

Here you can try out the synchronized display of PDF & Text yourself: Move your mouse over the words in the interactive screenshot and watch how the synchronous cursor runs through both documents at the same time.

Synchronized display of PDF and text. top: Side-by-side PDF view of the compared documents, bottom: The extracted text from both documents. All displays are synchronized with each other and show differences with colored highlights.

Everything in view.

The main window of PDiff consists of a fully synchronized display of both documents:

  • top: PDF view with a side-by-side display of document A and document B
  • bottom: Text view with a synoptic comparison of the extracted texts from document A and document B, i.e. corresponding text passages each at the same height

Differences found are clearly highlighted in both window halves by colored markings.

Advantages of the synchronized display.

This synchronized display gives you a unique insight into the comparison process: You see …

  • … where text was found and where not.
  • … whether special characters, accent marks and symbols are displayed correctly.
  • … whether spaces and hyphenations were recognized correctly.
  • … in which order the words were read and compared.
  • … whether differences are possibly only caused by incorrectly recognized letters of an OCR.
  • … on which characters style attributes such as bold, italic, underline, and strikethrough were recognized.
  • … whether numerical values and chemical/mathematical formulas were read correctly (sign, decimal point, order of digits, subscripts and superscripts).
What do your PDF files look like in the synchronized display?
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Report7 types of output formats.

With PDiff you can generate your comparison results not only for yourself, but also for

  • customers
  • suppliers
  • internal documentation (colleagues or supervisors)
  • external auditors, such as regulators
  • other software systems for further processing

And if you give something out of hand, then it is not enough that the reports look only acceptable. They just have to be perfect. The format and content must be correct.

That’s why PDiff offers you 7 types of output formats:

  • Tabular PDF report (for regulators like the EMA)
  • Annotated PDF A or B
  • Side-by-side PDF A + B
  • XML
  • CSV
  • PDiff projects
  • Return code for automation via CLI

The reports document comprehensibly and unambiguously changes and/or similarities with position, text and optional user comments.

The content and layout of reports can be configured to fit your needs.

So you can produce exactly the results you need to optimally present yourself and your work.

Output formats of PDiff: PDF, XML, CSV, PDiff Projects, Return Code

Output formats of PDiff. 7 output formats are available. Content and appearance are configurable.

Create comparison reports for your own files.
Downlaod trial version ›

FilterPower functions to filter out unimportant differences.

PDiff offers you the following 6 power functions, which allow you to achieve clear comparison results even with complicated documents:

  • Exclusion areas to hide irrelevant differences in headers and footers
  • Page ranges to exclude single or multiple pages such as title pages, table of contents, or appendices from the comparison
  • Text flow tool to synchronize different reading directions in complex, nonlinear layouts
  • Table tool to match the text flow of data in tables
  • Replace function to systematically exchange different characters or words in both documents, e.g. for lists with changed bullets (“-“ vs. “•”)
  • Comments and OK checkmarks to explain individual differences or to manually hide irrelevant differences via a check-off function
Without exclusion areas: Differences on each page due to the footer and margin notes in PDF B.
Without exclusion areas: Differences on each page due to the footer and margin notes in PDF B.
With exclusion areas: Footers and margins on all pages in PDF B excluded from comparison.
With exclusion areas: Footers and margins on all pages in PDF B excluded from comparison.
Without page ranges: Additional pages in the front matter and back matter pages of PDF B create numerous differences.
Without page ranges: Additional pages in the front matter and back matter pages of PDF B create numerous differences.
With page ranges: Front matter and back matter of PDF B excluded from comparison.
With page ranges: Front matter and back matter of PDF B excluded from comparison.
Without replace function: Many differences due to exchanged characters.
Without replace function: Many differences due to exchanged characters.
With replace function: Significantly fewer differences by replacing uniformly exchanged characters. Differences by irregular exchanged characters become clearly visible.
With replace function: Significantly fewer differences by replacing uniformly exchanged characters. Differences by irregular exchanged characters become clearly visible.

Compare text with PDF, Application to pharmaceutical packaging

Comparing apples and oranges? No problem.

With PDiff you can also compare documents where the layout differs widely: for example, check the press-ready layout against the copy text.

Special functions for packaging.

PDiff Professional also supports the comparison of rearranged texts. So you can check even complicated layouts of packaging against the original text. For example you can compare copy text with the text of a press-ready folding box that does not even have a defined text flow direction.

PDF comparison PDiff Icon

Did you know…

…that the English idiom to compare apples and oranges, as depicted in the PDiff icon, translates differently to other languages. Another common idiom - e.g. in French, German, Spanish, and Italian - uses the expression apples and pears to describe the comparison between dissimilar things.

Discover the power functions of PDiff for filtering out unimportant differences.
Download demo version ›

GearAutomation for high data volumes.

If you need to examine large document collections: PDiff Professional can be completely automated, either within the GUI or even without GUI for integration with other software systems.

Batch processing in the GUI.

A few mouse clicks, and the automation does the work for entire directories. Simply create PDF reports over all document pairs.

Compare PDFs with automation and batch processing

Automation via CLI interface.

Do you plan to integrate PDiff into your workflow or call it from other software systems? Through the CLI interface, PDiff may be operated as a command line program. Hence, you can integrate the powerful PDF comparison seamlessly in every possible automation solution.

PDF comparison PDiff, Automation via command line interface
Get started with PDiff's automated PDF comparison.
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Why compare documents with PDiff (and not with other tools)?

Because you need a solution that you can fully rely on. Which will not let you down with complicated documents. And which allows you to shine with your results thanks to tailor-made report formats.


Synchronized display of PDF & Text provides clear insights into the comparison process, so you can fully rely on the results.

With some comparison tools, you only see the text content and completely lose sight of your original PDF documents. With other tools, you only see the PDFs, but you never know exactly which text content was really compared behind the scenes.

Not so with PDiff. Here you see everything synchronized in an ingenious combination: the two PDFs side by side and the recognized text underneath.

Thanks to this display, with PDiff you know for sure what’s actually going on with the comparison and how to find the differences in your PDF documents.

Adobe logo

PDiff uses the Adobe® PDF Library™ for standard-compliant PDF processing without nasty surprises.

PDF is a global standard for reliable electronic documents and ISO standard for archiving electronic documents. PDiff uses the Adobe® PDF Library™ to ensure a platform-independent, accurate display. And to guarantee a reliable and consistent text analysis.


The powerful comparison engine will not let you down with complicated documents.

The most common reason that users are frustrated by comparison tools and switch back to manual proofreading: The display of too many irrelevant, unaccountable differences. And just when the software is needed the most – with more complicated documents – the benefits go to zero.

To make sure that does not happen to you with PDiff, we’ve added 6 power functions to the software that let you filter out unimportant differences in a surprisingly easy way. So, even with complicated inputs, you can rely on PDiff to do a lot of the work for you.

Light bulb

With know-how and horsepower to the finish, so you are quickly free again for creative tasks.

Comparing documents is probably not one of your core tasks. Your exciting, creative, interesting work takes place before or after. It is therefore all the more important that PDiff brings you quickly to your destination.

Thanks to the intuitive and field-proven interface of PDiff, you can immediately start comparing your files. Without training or reading thick manuals.

And also under the hood, everything is geared for speed: 64-bit technology and parallel processing on multi-core CPUs compare even 100-page documents in 17 seconds2.


Cloudless: PDiff works without the cloud. Your confidential documents stay with you.

Your confidential data remains on your computer. Your documents will never be transferred over the internet.

In addition, a speed factor: The calculations are completely locally. You benefit directly from the computing power of your workstation computer.

More information can be found here: Cloudless – Your data belongs to you!.


Flexible output formats let you deliver brilliant results.

Do you need proof of the unaltered text or the exact changes made?

With other tools, you can usually only produce one type of output where the format and content cannot be changed.

With PDiff you can create 7 types of result reports to get output in form and content according to your wishes. So that you deliver brilliant results that make you and your work shine.

Challenge PDiff with your PDFs that would not compare with other programs.
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1 The average human reading speed when proofreading texts is 200 words per minute.

2 Speed measurement of PDiff: Measured for a 100-page sample document with 59037 words and 590 word differences (1%) on a MacBook Pro, 2,9 GHz Intel Core i7, 16GB RAM by calling PDiff in CLI mode. The computing time including report generation (annotated PDF A + B) is 17s.

3 According to a comparative study by Ray Panko, University of Hawaii on proofreading error rates, the human recognition rate of word errors is about 75%.