"Quick Open" vs Exact Open — What Changes

There is some measuring before a document opens

To draw a document looking like the original, the width of every character has to be measured first. This is where it is decided where lines wrap and where pages break. For a large document, this takes time.

"Quick open" only appears for long Word documents (500 paragraphs or more). It does not appear for short documents or PDFs — there is nothing to wait for.

Two choices

1. Start editing — measures the widths, then opens. Slower, but the line breaks and page breaks are closest to the original. This is the default. (For a document with no editable text in the body, the button in the same spot reads "Open anyway".)
2. Fast open — opens without measuring. Appears quickly, but the line breaks and page breaks differ from the original.

What changes and what stays

Even with Fast open, the text and formatting stay the same. Bold, colors, tables and images all remain. What changes is where lines wrap and where pages break, and the shape of the fonts used on screen may also differ from the original.

What matters is the downloaded file. Whichever way you opened it, the saved .docx opens in Word looking like the original. It only looks different on screen here.

If you need to fix one spot in a hurry and pass it on, Fast open is convenient. If you need to check the printed look on screen, open it with "Start editing".