Qualtrics - Dragging text box bigger or small
You cannot return a dragged text box to its default size, and the sizes may differ from the builder view to the preview.
Text Box options
In Text entry question type you have the following choices Single line, Multiple lines, Essay text box, and Password. In the builder the Multiple lines and Essay will show as single line. If you try to make the texts boxes different sizes by dragging them they cannot be reset to the default size and they can show much different in the preview then the builder.
When you click to edit validation in the Form field question type, you have additional flexibility over the sizes. For each field, you have the following options: Short, Medium, Long, and Essay.
You can input up to 20,000 characters in a single text box, regardless of its size.