We often get asked by clients how many fields to include in online forms such as forms on a Contact Us page or an email newsletter signup form.
We recently came across an infographic from FormStack (a provider of online forms that we use on our own websites) that shared the results of research into "best practices" for maximizing form conversions. All studies confirmed that, as we regularly advise clients, fewer form fields increases conversions (i.e., submissions).
For example, one study deployed two identical Contact Us forms, except that one had 4 fields and one had 11 fields. The 4-field form only asked for the most essential pieces of information such as email address, while the 11-field form incorporated additional questions such as street address and fax number. The 4-field form resulted in 160% more conversions.
The same study also found that the number of questions on a form directly correlates with the rate of people dropping off without completing the form.
Another study that researched 40,000 contact forms found that conversion rates improved by 50% when the number of form fields reduced from four to three.
But let's say you need someone's address in a particular form (e.g., to mail a report). You can still reduce the number of fields by, for example, asking for zip code, and then accessing a database that will link the zip code to appropriate city and state combinations the user can then verify and not have to enter manually.
The infographic shares other form "best practices" as well with respect to issues such as error handling (e.g., telling a user that a required field is missing) and form design.