The complete knowledge base about ARender - How to install it and how to configure it as needed

Document comparison

Compare two documents

Image comparison feature
The image comparison is a feature available from version 4.4.0

Manual processing

To do a comparison between two documents, right click on a document’s thumb in the navigation panel and select Open as new and compare or Open as new and compare images if both documents are images.

Case of textual documents


The chosen document opens next to the current one, then the comparison results are displayed.


Case of image documents


The chosen document opens next to the current one, then the comparison result is displayed as a new image.


Automatic comparison on start up

To automatically start the comparison after the application loading, use the following parameter:


The comparison will only be triggered if at least two documents are loaded.

The first document of these will be opened on the left and the second one on the right.

If both documents are images, then the image comparison will be triggered.

Close comparison mode

  • To go back to the simple view mode, click on the red cross in the upper right corner of the document to close.


  • It is also possible to close the comparison mode by right clicking on a document and select Close multiView.


Parse comparison results

Each difference type between two documents corresponds to a specific color:

Color Meaning
Green Added line
Red Removed line
Grey Modified line
Orange Modified text on a specific line


Browse results


Clicking on the Next result or Previous result button will redirect to the closest one, regardless of the document.


Synchronized scroll between documents

The synchronized scroll function is enabled by default when a comparison is done. It can be disabled using the corresponding button in the top panel.

Result’s match

Clicking on a specific result redirects to the matching line on the other document.


Comparison mode’s specifications

  • The multi-view mode comes with the concept of current document which is defined has the last document hovered.

    This document is used for most of functionalities: Annotations, Download, Printing, Text searching, Page rotation, …

  • Document changing using navigation panel’s thumbs is disabled.

    Only thumbs corresponding to documents currently opened in comparison mode allow to jump to the selected page on it.

How define the focus of document by click

To define the focus of the document by click use the parameter:


The image comparison result

After launching image comparison, a new view is displayed where you can see the both images compared, a configuration box in which you can modifiate the “fuzz”, “highlight color” and “lowlight color” values, and the image result.


The image comparison is based on mathematical calculations influenced by the value of the “fuzz”. A greater “fuzz” value means a less accurate pixel comparison calculation.

By default, the differences are the red zones (highlight color) and the pixels that are not considered different are colorless (lowlight color).

Download documents with comparison results

With UI

Once the comparison is done, a download button is available to download the two documents side by side with their comparison results on it.


With servlet

Example of URL allowing the servlet to be used to perform a comparison and then download the side-by-side documents with their comparison results on it.