Choose Tools > Compare Files.

Click Select File at left to choose the older file version you want to compare. Click Select File at right to choose the newer file version you want to compare.

Click Change File and then choose an already opened file or browse to select your desired file. Click the Swap arrows icon between the thumbnails to swap the position of the old and new files.

To ignore differences between the graphic elements, select the Compare Text Only checkbox.

You can modify settings by clicking the Settings gear icon, which opens the following dialog box.

1. You can limit the comparison to a portion of the documents by entering the page numbers in the Old File and New File fields.
2. Under Document Description, select the type of documents that you are comparing.
   • Select Autodetect to let Acrobat decide.
   • Reports, Spreadsheets, Magazine Layouts: Compares the content as one continuous text body, from end to end.
   • Presentation Decks: Looks at each slide or page as a mini-document, and matches ones that are similar. Then compares the content of each matching document. Identifies documents that have moved, such as slides in a presentation.
   • Scanned Documents, drawing or illustrations: Creates an image capture of each scanned page and compares pixels. Looks at each scanned page and matches ones that are similar. It also identifies pages that are in a different order. This option is useful for comparing images or architectural drawings.
     
     Tip: If your document content can reflow across pages, select Reports, spreadsheets, magazines layouts; otherwise select Presentation Decks. For comparing scanned files, select Scanned documents, drawings or illustrations.
     • With either the reports or presentation options selected, the Compare Text Only option identifies only the text differences between two documents.
     • With Scanned Documents selected, the text is compared separately from the graphics, and then the results are combined. In documents containing magazine advertisements that have text on top of background image art, a reflowed passage is compared in text-only mode. The artwork is compared separately in the background. The differences (both text and line art and images) are combined into a single results document.
3. Show in Report, select the elements of the documents for which you want to see the differences in the compare report.
   
   Note: The text option can be used with any document type. It is designed for comparing text in large documents (250 pages or more). It also compares text between documents that have background artwork on each page, which slows processing.
   
4. Click OK.
   

Click Compare.

Acrobat displays the results in a new document. The first page provides an easy-to-scan summary of all file differences.

Click the Go to First Change button to begin reviewing each difference in detail.

Select how you want to review the differences.

• Side-by-side view: Use the Side-by-Side (Ctrl+\) view to see a parallel view of results where the differences are shared in highlighted bands. The old file is displayed on the left and the new file is displayed on the right, with the changes highlighted in each band connecting across the files for easier review. Click a band to display a pop-up note detailing all of the changes within the band. You can also click the highlighted content to open the pop-up.

Right-click a change or its pop-up and set an appropriate status for the change.

• Single page view: Use the Old File or New File button (Ctrl+/) on the toolbar to see the individual file with all changes highlighted.

To review all the changes:

• Use the Filter and Show options.

By default, annotations, formatting, and background differences are turned off. To see these changes in the report, select these options from the Filter menu in the toolbar. You can also filter comparison results by selecting specific types of changes in the Filter menu. From the Show menu, you can select an option to show or hide legends, row highlights, or results.

• Use the Previous Change (Ctrl+.) or Next Change (Ctrl+,) button to go through the changes one-by-one.

The Previous Change and the Next Change button are also available in the pop-up notes detailing the changes.

• Use the right pane. Click the triangle at the center of the right Acrobat window to open the right pane. This pane lists all the changes visible in the Compare Results report. Use the search text box to search for any specific change.

Save the Compare Results file (File > Save). Click the cross button at the top right of the toolbar to close the Compare Files tools.