Compare Documents vs. Overlay Pages | Revu 21

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Applies to:

  • Revu 21
You must have a Core or Complete Bluebeam plan to access these features.

Revu provides two ways to compare original drawings with their revisions during the Design Review stage. The Compare Documents feature highlights differences between two PDFs using cloud markups, while the Overlay Pages feature merges PDF content from two or more files and displays any edited content in a separate color.

This article covers the key differences and similarities between both features and shows you how to use Compare Documents and Overlay Pages for your drawing reviews.


Compare Documents allows you to see where differences occur between two PDFs. Overlay Pages allows you to see what the differences are between two or more PDFs. You use both features to create an Overlay PDF that includes the highlighted differences from Compare Documents

While Compare Documents can work with scanned drawings, both Compare Drawings and Overlay Pages work best with high quality vector PDFs.

Compare Documents

  1. Go to Document > Compare Documents.
  2. For Documents A and B, use the dropdown to choose from the list of open PDFs, or click Browse to select files from the Windows File Explorer.
    To ensure the differences between both PDFs are highlighted properly, Document A should be the original drawing and Document B should be the revised version.
  3. Under Output, choose an output folder to save the new comparison file.
  4. Select OK.

Revu will display a new PDF ending in _Diff with the differences between the original and revised drawings highlighted with orange cloud markups. You can also access these markups within the Markups List for easy tracking and reporting.

Select Advanced Options to further customize the comparison PDF, including the cloud markup that will highlight the differences between the original and revision.

Overlay Pages

  1. Go to Documents > Overlay Pages.
  2. Select Add Files to choose the PDFs to compare from files you have open or from the File Explorer.
    Unlike Compare Documents, you can choose more than two drawings to compare as multiple layers.
  3. Choose the alignment method:
    • Page Align: Revu places your PDFs directly on top of each other. Recommended for drawings that have minor revisions but are otherwise the same in terms of scale and position on the page. This is the default option.
    • Auto Align: Revu automatically finds points of alignment between your PDFs. Recommended for drawings that vary in size and scale.
    • Manual Align: Revu allows you to select three points that will act as anchor points between the drawings. You must select the same three points in the same order for all your selected drawings. Recommended when Auto Align doesn’t work as intended.
  4. Select OK.

Revu will display a new PDF named Overlay that displays content from the chosen drawings as layers in different colors. Select Edit Defaults in the Overlay Pages dialog to customize the appearance and positioning of the overlay.

Create a Compare + Overlay PDF

In a Compare and Overlay PDF, you have the additional benefit of easily spotting suggestions or revisions via the orange cloud markups that highlight differences between two drawings.

Since you need to apply both the Compare Documents and Overlay Pages functions for this process, working with scanned PDFs won’t produce the desired result.

Export the highlighted differences

  1. Go to Document > Compare Documents.
  2. Select the PDFs you’re comparing for Document A and Document B.
    Make sure Document A is the original drawing and Document B is the revised version.
  3. Select OK.
  4. In the new comparison PDF, open the Markups List.
  5. Go to Markups List > Markups > Export Markups
  6. Save the markups in a folder/location you can easily access again for importing later.
  7. After exporting the markups, save the Compare Documents PDF by going to File > Save As.
  8. Close the comparison PDF.

Create the overlay

  1. Go to Document > Overlay Pages.
  2. Choose the same two PDFs you used for the Compare Documents process.
  3. Select OK.
  4. In the new overlay PDF, open the Markups List.
  5. Go to Markups List > Markups > Import.
  6. Select the markups export file from the Compare Documents PDF.
  7. Select OK.

Now all the markups, including the highlighted differences from the Compare Documents PDF, will be available on the Overlay PDF.

Compare + Overlay Difference


Revu 21

Drawing Management

PDF Management

Document Processing

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