Open the first file that you want to compare in Navisworks.
Click Home tab > Project panel > Append drop-down > Append , locate the second file, and click Open.
Hold down CTRL key, and select both files in the Selection tree .
Click Home tab > Tools panel > Compare .
In the Compare dialog box, the Find Differences In area, select the check boxes for all required options.
In the Results area, select the check boxes to control how the comparison results are displayed:
Save as Selection Sets. Saves the items that you are comparing as a selection set. You can then use this set for later comparisons between the same items.
Save Each Difference As Set. Saves the resulting differences found in the comparison between the two items as a selection set for later analysis. The selection set will also have a comment attached detailing the differences in more depth.
Remove Old Results.Removes any selection sets resulting from a previous comparison, in order to reduce confusion when looking at the results.
Hide Matches. Hides all items that turn out to be the same in the comparison, when the comparison finishes.
Highlight Results. Highlights each resulting difference with a color override, when the comparison finishes. You can reset the colors back by clicking Home tab > Project panel > Reset All drop-down > Appearances .
Click OK.