One of the most important things to consider when designing forms is it’s scanability. Before making the decision to even begin filling out a form, most users will quickly scan the form, taking a quick mental inventory of what will be required of them. If the user feels that the form is too long or too complicated to be worth their time and effort, they may likely decide not to complete it at all. By vertically stacking your fields and sticking to a single column layout, your form fields will appear more organized and will be easily scanable from top to bottom.

There are a few related form fields, however, that are much more acceptable to list side by side. To make your form seem slightly shorter, try listing closely grouped items, such as first and last name, city and state, and dates next to each other horizontally.