Include a label
Every text field should have a label. A field without a label is ambiguous and not accessible.
Review label-less designs
In rare cases where context is sufficient and a label could be absent, make sure to have the design reviewed and approved by an accessibility expert. These should still include an aria-label in HTML (depending on the context, aria-label or aria-labelledby).
Follow capitalization rules
Field labels should be in sentence case.
Mark the minority of text fields in a form as required or optional
In a single form, mark only the required fields or only the optional fields, depending on whichever is less frequent in the entire form. If most of the text fields are optional, only the required fields should be give an asterisk or have labels appended with "(required)". If most of the text fields are required, only the optional fields should be appended with "(optional)". An asterisk should never be used to note that a text field is optional.
Use help text to show hints, formatting, and requirements
The description in the help text is flexible and encompasses a range of guidance. Sometimes this guidance is about what to input, and sometime it's about how to input. This includes information such as:
- An overall description of the input field
- Hints for what kind of information needs to be input
- Specific formatting examples or requirements
The help text's message should not simply restate the same information in the label in order to prompt someone to interact with it. Don't add help text if it isn't actually relevant or meaningful to a user in order to try to maintain layout continuity with other inputs that require help text.
Don't use placeholder text
Putting instructions for how to complete an input, requirements, or any other essential information into placeholder text is not accessible. Once a value is entered, placeholder text is no longer viewable; if someone is using an automatic form filler, they will never get the information in the placeholder text.
Instead, use the help text description to convey requirements or to show any formatting examples that would help user comprehension. If there's placeholder text and help text at the same time, it becomes redundant and distracting, especially if they're communicating the same thing.
Switch help text with error text
The help text area also displays an error message. When a text field already includes help text and an error is triggered, the help text is replaced with error text. Once the error is resolved, the help text description reappears below the field.
Since one gets replaced by the other, the language of the help text and error text need to work together to convey the same messaging. Help text explains the requirement or adds supplementary context for how to successfully complete the input. Error text tells a user how to fix the error by re-stating the input requirements or describing the necessary interaction. Make sure that the help text and the error text include the same essential information so that it isn't lost if one replaces the other like password requirements.
Write error text that shows a solution
Write error messaging in a human-centered way by guiding a user and showing them a solution — don't simply state what's wrong and then leave them guessing as to how to resolve it. Ambiguous error messages can be frustrating and even shame-inducing for users. Also, keep in mind that something that a system may deem an error may not actually be perceived as an error to a user.
Error text should be written in 1-2 short, complete sentences and in a clear and straightforward way. End sentences with a period, and never with an exclamation point. For text fields, the nature of the error is often related to something that needs to be fixed for in-line validation, so a helpful tone is most appropriate. For example, if someone were to miss filling out a required field that asks for their email address, write the error text like you're offering a hint or a tip to help guide them to understand what needs to go in the missing field: "Enter your email address."