Compare Documents vs. Overlay Pages

Applies to:

  • Revu 21
  • Revu 20
  • Revu 2019
  • Revu 2018

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

In this article, we’ll go over the key differences and similarities between both features and show you how to create a Compare and Overlay PDF for your drawing reviews.

For Revu 21 users, you must have a Core or Complete subscription plan to access these features.


Although both Compare Documents and Overlay Pages are used to analyze drawings and revisions efficiently, each feature has its own unique benefits. Reference the table below to decide which tool best fits your project’s needs:

Feature/Benefit Compare Documents Overlay Pages
Creates a 3rd PDF without altering the original or revised drawing
Can compare more than two PDFs  
Works with scanned PDFs  
Drawing differences included in the Markups List  

Compare Documents

The Compare Documents function is widely used for official review processes. To watch a quick introduction to this feature, please see our training video

Follow these steps to get started:

  1. Open Revu.
  2. Go to Document > Compare Documents.
  3. In the Compare Documents dialog box, choose Document A by clicking the double dot icon, which will launch the File Explorer. Choose Document A
  4. Repeat Step 3 for Document B.
    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.
  5. Because the Compare Documents function creates a 3rd PDF, you can choose an output folder to save the new file.
  6. If you’re working with scanned PDFs that are misaligned, you can use Select Window or Pick Points to manually adjust alignment.
  7. Under Other Options, you can select a split screen view for the comparison PDF as well as the comparison type. Scanned Documents
    One of the main benefits of using Compare Documents is being able to work with scanned PDFs, which isn’t possible with Overlay Pages.
  8. Select Advanced Options to further customize the comparison PDF, including the cloud markup that will highlight the differences between the original and revision. Advanced Options for Markup
  9. When finished choosing, select OK.

A new PDF will open in Revu. Per default, the differences between the original and revised drawings will be highlighted with orange cloud markups. You can also access these markups within the Markups List for easy tracking and reporting.

Differences in Markup List
Cloud markups will display any discrepancies between the original and revised PDFs and are automatically labeled with “Difference” as their Subject in the Markups List.

Overlay Pages

Another way to compare original and revised drawings in Revu is via Overlay Pages. This function is especially useful if you need to see drawing changes at a quick glance and/or if you’d like to compare more than two versions. You can watch an overview about the Overlay Pages feature here

To get started, follow these steps:

  1. Open Revu.
  2. From the Navigation Bar, go to Documents > Overlay Pages.
  3. In the Overlay Pages dialog box, click Add to choose the PDFs you’d like to compare from the File Explorer.
    Unlike Compare Documents, you can choose more than two drawings to compare as multiple layers.
  4. If you need to modify the pages or page ranges, select a document individually and click Modify.
  5. To change the colors for each layer, select Edit Defaults.
  6. In the Overlay Defaults dialog box, you can also adjust the position and other settings. Overlay Defaults
  7. When finished editing default settings, click OK.
  8. If you’re overlaying drawings that are different sizes, you can select Align Points from the Overlay Pages dialog box. Align Points Overlay
    To learn more about aligning PDFs with Overlay Pages, please see this article.
  9. After choosing documents, editing defaults, and/or aligning points, click OK in the Overlay Pages dialog box.

A new Overlay PDF will open in Revu, displaying content from the chosen drawings as layers in different colors.

Overlay Example
The Overlay Pages function shows that the sizes of these rooms have changed at a quick glance.

Create a Compare + Overlay PDF

If you want the best of both worlds while reviewing documents, there’s a way to create an Overlay PDF that includes the highlighted differences (cloud markups) from the Compare Documents feature. Just follow these steps:

Because you’ll need to run through both the Compare Documents and Overlay Pages functions for this process, working with scanned PDFs won’t produce the desired result.
  1. Open Revu.
  2. First, go to Document > Compare Documents.
  3. Select the documents you’re comparing for Document A and Document B. Make sure Document A is the original drawing and Document B is the revised version.
  4. Click OK.
  5. In the new comparison PDF, open the Markups List.
  6. Go to Markups List > Markups > Export Markups (Ctrl+F2). Export Markups
  7. Save the markups in a folder/location you can easily access again for importing later.
  8. After exporting the markups, save the Compare Documents PDF by going to File > Save As.
  9. Close the comparison PDF.
  10. Next, create the overlay PDF by going to Document > Overlay Pages.
  11. Choose the same two PDFs you used for the Compare Documents process.
  12. Click OK.
  13. In the new overlay PDF, open the Markups List.
  14. Go to Markups List > Markups > Import (Ctrl+F3)
  15. Select the markups export file from the Compare Documents PDF.
  16. In the File Explorer, click OK.

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

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

If you’d like to learn more helpful hacks for working efficiently in Revu, visit our Tips and Tricks page!


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