How to Compare Documents Side-by-Side in Word 2016 and Prior
The easiest way to compare two Word documents is to view them side by side and scroll them both at the same time. Here are the Word shortcuts that will make it easier to compare changes between two documents, line by line.
The steps below apply to Word 2016 and earlier,
1. Open the two Word documents you want to compare.
2. Go to the View tab and click the View Side by Side icon. It looks like two pages next to each other.
3. Select which document to compare with your current one.
Word will automatically arrange the two Word windows horizontally so you can compare them side by side. Synchronous scrolling will also be turned on automatically, so you can scroll both documents at once.
To turn off either, click on the "View Side by Side" or "Synchronous Scrolling" button.