Someone who uses your app or website has a
particular goal. Often, the one thing standing between the user and their goal
is a form. Forms remain one of the most important types of interactions for
users on the web and in apps. Forms are often considered the final step in the
journey of completing their goals. Forms are just a means to an end. Users
should be able to complete them quickly and without confusion.
In this article, you’ll find best practices for form design
that have been gleaned from usability testing, field testing, eye-tracking
studies and actual complaints from disgruntled users. These techniques — when
used correctly — enable designers to produce faster, easier and more productive
The components of forms
The typical form has the following five
- Structure: This includes the order of fields, the form’s appearance on the page and the logical connections between multiple fields.
- Input fields: These include text fields, password fields, checkboxes, radio buttons, sliders and any other fields designed for user input.
- Field labels: These tell users what the corresponding input fields mean.
- Action button: When the user presses this button, an action is performed (such as submission of the data).
- Feedback: The user is made to understand the result of their input through feedback. Most apps and websites use plain text as a form of feedback. A message will notify the user about the result and can be positive (indicating that the form was submitted successfully) or negative (“The number you’ve provided is incorrect”).
Forms may also have the following
- Assistance: This is any explanation of how to fill out the form.
- Validation: This automatic check ensures that the user’s data is valid.
This article covers many aspects related to
structure, input fields, labels, action buttons, and validation.
A form is a type of conversation. And like
any conversation, it should consist of logical communication between two
parties: the user and the app. The form structure defines a skeleton for your
form and that is the reason why we explore form
in the context of form structure.
Ask only what’s required
Make sure to ask only what you really need.
Every extra field you add to a form will affect its conversion rate. Always
consider why you are requesting certain information from the user and how you
will use it.
Order the form logically
Ask details logically from the user’s
perspective, not from the application or database’s perspective. Typically,
asking for someone’s address before their name would be unusual.
Group related information
Group related information into logical
blocks or sets. The flow from one set of questions to the next will better
resemble a conversation. Grouping together related fields will also help users
make sense of the information they must fill in. Compare how it works in the
contact information form below.
One column vs. multiple columns
When it comes to web design, designers
often experiment with website layouts to convey visual interest
for the site’s visitors. However, when it comes to form design, it’s better to
resist the temptation to have any layouts that have more than one column.
One of the problems with arranging form
fields into multiple columns is that users will likely interpret the fields
inconsistently. If a form has horizontally adjacent fields, then the user must
scan in a Z pattern, slowing the speed of comprehension and muddying the path
to completion. But if a form is in a single column, the path to completion is a
straight line down the page.
On the left, one of many ways to interpret
how the form fields relate when they are arranged in a standard two-column
layout, versus on the right, a straight line down the page.
Input fields are what enable users to fill
in a form. Various types of fields exist for the information you need: text fields,
password fields, dropdowns, checkboxes, radio buttons, date-pickers and more.
Number of fields
When it comes to designing forms, a rule of thumb is that shorter is better. And this certainly seems intuitive: less effort on the part of the user will lead to higher conversion. Thus, minimize the number of fields as much as possible. This will make your form feel less bloated, especially when you’re requesting a lot of information. Displaying only five to seven input fields at a given time is a common practice.
Mandatory vs. optional
Try to avoid optional fields in forms. But
if you use them, at least clearly distinguish which input fields may not be
left blank. The convention is to use an asterisk (*) for required fields or the
word “optional” for non-required fields (which is preferable in long forms with
multiple required fields). If you decide to use an asterisk for mandatory
fields, show a hint at the bottom of the form explaining what the asterisk is
Setting default values
Many best practices for form design stress the risk of
using static defaults (predefined values in input fields). It’s better to avoid
setting default values unless you believe a large portion of your users (say,
95% of them) will select the same values. People scan online forms quickly, and
they don’t spend much time parsing through all of the choices. As a result,
they can easily skip something that already has a value.
But this rule doesn’t apply to smart
defaults, which are pre-set values based on available information about the
user. Smart defaults can make form
completion faster and more accurate. For example, preselect the user’s country
based on geo-location data. Still, use these with caution, because users tend
to leave preselected fields as they are.
Field masking is a technique that helps
users format inputted text. A mask appears once a user focuses on a field, and
it formats the text automatically as the field is being filled out, helping
users to focus on the required data and to more easily notice errors. In the
example below, the parentheses, spaces, and dashes are applied automatically as
the phone and credit card numbers are entered. This simple technique saves time
and effort with phone numbers, credit cards, currencies and more.
Designing forms for desktop: make form keyboard-friendly
Users should be able to focus on and edit every field using only the keyboard. Power users, who tend to use the keyboard heavily, should be able to easily tab through and edit fields, all without lifting their fingers off the keyboard. You can find detailed requirements for keyboard interaction in the W3C’s guidelines on design patterns.
Designing forms for desktop: autofocus for input field
Autofocusing a field gives the user an
indication and a starting point to quickly begin filling out a form. Provide a
clear visual signal that focus has moved there, whether by changing color,
fading in a box, flashing an arrow, whatever. Amazon’s registration form has
both autofocus and visual indicators.
Designing forms for mobile: match keyboard to input
Phone users appreciate apps that provide
the appropriate keyboard for the text being requested. Implement this
consistently throughout the app, rather than merely for certain tasks but not
Limit typing (autocompletion)
With more and more people using mobile screens, anything that can be done to prevent unnecessary typing will improve the user experience and decrease errors. Autocompletion makes it possible to eliminate a huge amount of typing. For example, filling out an address field is often the most problematic part of any registration form. A tool such as Place Autocomplete Address Form (which uses both geolocation and address prefilling to provide accurate suggestions based on the user’s exact location) enables users to enter their address with fewer keystrokes than regular input fields.
Written labels are one of the primary ways
to make a UI more accessible. A good label tells the user the purpose of the
field, maintains its usefulness when the focus is on the field itself and remains
visible even after the field has been filled in.
Number of words
Use succinct, short, descriptive labels (a
word or two) so that users can quickly scan your form. Previous versions of
Amazon’s registration form contained a lot of words, which resulted in slow
completion rates. The current version is much better and has short labels.
Sentence case vs. title case
In most digital products today, there are
two ways to capitalize words:
- Title case: capitalize every word. “This Is Title Case.”
- Sentence case: capitalize the first word. “This is sentence case.”
Sentence case used for labels has one
advantage over title case: It is slightly easier (and, thus, faster) to read.
While the difference for short labels is negligible (“Full Name” and “Full
name”), for longer labels, sentence case is better. Now You Know How Difficult
It Is to Read Long Text in Title Case.
Avoid all caps
Never use all caps, or else the form will
be difficult to read and much harder to scan because there will be no variation
in character height.
Alignment of labels: left vs. right vs. top
Matteo Penzo’s 2006 article on label placement suggests that forms are completed faster if labels are on top of the fields. Top-aligned labels are good if you want users to scan the form as quickly as possible.
The biggest advantage of top-aligned labels
is that different-sized labels and localized versions can more easily fit the
UI. (This is especially good for screens with limited space.)
The biggest disadvantage of left-aligned
labels is that it has the slowest completion times. This is likely because of
the visual distance between the label and the input field. The shorter the
label, the further away it will be from the input. However, a slow completion
rate isn’t always a bad thing, especially if the form asks for sensitive data.
If you are asking for something like a driver’s license number or a social
security number, you might deliberately want to slow down users a bit to make
sure they enter it correctly. Thus, the time spent reading labels for sensitive
data is insignificant. Left-aligned labels have another disadvantage: They
require more horizontal space, which might be a problem for mobile users.
The big advantage of right-aligned labels is the strong visual connection between the label and input. Items near each other appear to be related. This principle isn’t new; it derives from the law of proximity, from Gestalt psychology. For short forms, right-aligned labels can have great completion times. The disadvantage is discomfort; such forms lack that hard left edge, which makes it less comfortable to look at and harder to read.
Takeaway: If you want users to scan a form
quickly, put labels above the fields. The layout will be easier to scan because
the eye will move straight down the page. However, if you want users to read
carefully, put labels to the left of the fields. This layout will slow down the
reader and make them scan in a Z-shaped motion.
Inline labels (placeholder text)
A label set as a placeholder in an input
field will disappear once the field gains focus; the user will no longer be
able to view it. While placeholder text might work for two-field forms (a
simple log-in form with username and password fields), it’s a poor substitute
for visual labels when more information is required from the user.
Once the user clicks on the input field, the label will disappear, and so the user cannot double-check that they wrote what was being asked of them. This increases the chance of error. Another problem is that users could mistake placeholder text for prefilled data and, hence, ignore it (as Nielsen Norman Group’s eye-tracking study confirms).
A good solution for placeholder text is a
floating label. The placeholder text would be shown by default, but once an
input field is tapped and text is entered, the placeholder text fades out and a
top-aligned label animates in.
Takeaway: Don’t just rely on placeholders;
include a label as well, because once a field has been filled out, the
placeholder will no longer be visible. Use a floating label so that users are
sure they’ve filled out the correct field.
When clicked, an action button triggers
some activities, such as submission of the form.
Primary vs. secondary actions
A lack of visual distinction between
primary and secondary actions can easily lead to failure. Best practices for form design says that reducing
the visual prominence of secondary actions minimizes the risk of error and
reinforces people’s path to a successful outcome.
Complex forms usually need a back button.
If such a button is located right below an input field (like in the first
screenshot below), a user could accidentally click it. Because the back button
is a secondary action, make it less accessible (the second form below has the
right location for buttons).
Avoid generic words such as “Submit” for
actions, because they give the impression that the form itself is generic.
Instead, state what action the button will perform when clicked, such as
“Create an account” or “Subscribe to weekly offers.”
Multiple action buttons
Avoid multiple action buttons because they
might distract users from their goal of submitting the form.
The reset button is pure evil
Almost all best
practices for form design stress the importance of skipping a
reset button. This button rarely helps users and often hurts them. The web
would be a happier place if almost all reset buttons were removed.
Make sure action buttons look like buttons:
Indicate that it is possible to click or tap them.
Design the “Submit” button in a way that
clearly indicates the form is being processed after the user’s action. This
provides feedback to the user while preventing double submission.
Form validation errors are inevitable and
are a natural part of data entry (because users are prone to making errors).
Yes, error-prone conditions should be minimized, but validation errors will
never be eliminated. So, the most important question is, How do you make it
easy for the user to recover from errors?
Users dislike having to go through the
process of filling out a form, only to find out upon submission that they’ve
made an error. Especially frustrating is completing a long form and upon
pressing “Submit,” you are rewarded with multiple error messages. It’s even
more annoying when it isn’t clear what errors you’ve committed and where.
Validation should inform users about the correctness of the text as soon as the user has inputted the data. The primary principle of good form validation is this: Talk to the user! Tell them what is wrong using the right words and color palettes. Real-time inline validation immediately informs the user about the correctness of their data. This approach allows them to correct any errors faster, without having to wait until they press the “Submit” button to see the errors.
However, avoid validating each keystroke
because, in most cases, you simply cannot verify until someone has finished
typing an answer. Forms that validate during data entry punish the user as soon
as they start entering data.
On the other hand, forms that validate
after data entry do not inform the user soon enough that they’ve fixed an
Mihael Konjević, in his article “Inline Validation in Forms: Designing the Experience,” examines different validation strategies and proposes a hybrid strategy to satisfy both sides: Reward early, punish late.
- If the user enters data in a
field that was in a valid state (i.e. previously inputted data was valid), then
validate after data entry.
- If the user enters data in a
field that was in an invalid state (i.e. previously entered data was invalid),
then validate during data entry.
Jef Raskin once said, “The system should treat all user input as sacred.” This is true for forms. It’s great when you start filling in a form and then accidentally refresh the page but the data remains in the fields. Tools like Garlic.js help you to persist a form’s values locally until the form is submitted. This way, users won’t lose any precious data if they accidentally close the tab or browser.
Conversational interfaces: new ways of designing forms
Recently, we’ve seen a lot of excitement around conversational interfaces and chatbots. Several trends are contributing to this phenomenon, but one in particular is that people are spending more time on messaging apps than on social networks. This has led to a lot of experimentation with supporting a range of interactions, such as shopping, in threaded conversations, often in a way that mimics messaging. Evan an established element like web forms have undergone a change to adapt to this trend. Designers are looking to transform traditional web forms into interactive conversational interfaces.
Natural language interface
Every interface is a conversation.
Traditional forms (the ones we design every day) are quite similar to a
conversation. The only difference is the way we ask questions. But what if we
designed our forms to ask questions in a format that more closely reflects real
human (not machine) conversation? So, instead of communicating with a machine
on its own inhuman terms, you would interact with it on yours. The form shown below
creates a conversational context, facilitating understanding without relying on
the traditional elements of web forms (such as labels and input fields).
Conversational Form is an open-source concept that easily turns any form on a web page into a conversational interface. It features conversational replacements of all input elements, reusable variables from previous questions, and complete customization and control over the styling. This project represents an interesting shift in how we think about user experiences and interactions, leaning more towards text-based conversation to help users achieve their goals.
When it comes to designing
forms, it’s vital to remember that users can be
reluctant to fill out forms, so make the process as easy as possible. Minor
changes — such as grouping related fields and indicating what information goes
in each field — can significantly increase usability.
Keep in mind that the following best practices for form design listed in this article are only half of a battle. Usability testing is simply indispensable in form design. You also need to test your design with your users. Very often, testing with just a few people or simply asking a colleague to go through a prototype can give you a good insight into how usable a form is.