HTML attribute: required
The Boolean required
attribute, if present, indicates that the user must specify a value for the input before the owning form can be submitted.
The required
attribute is supported by {{HTMLElement("input/text","text")}}
, {{HTMLElement("input/search","search")}}
, {{HTMLElement("input/url","url")}}
, {{HTMLElement("input/tel","tel")}}
, {{HTMLElement("input/email","email")}}
, {{HTMLElement("input/password","password")}}
, {{HTMLElement("input/date","date")}}
, {{HTMLElement("input/month","month")}}
, {{HTMLElement("input/week","week")}}
, {{HTMLElement("input/time","time")}}
, {{HTMLElement("input/datetime-local","datetime-local")}}
, {{HTMLElement("input/number","number")}}
, {{HTMLElement("input/checkbox","checkbox")}}
, {{HTMLElement("input/radio","radio")}}
, {{HTMLElement("input/file","file")}}
, types along with the {{HTMLElement("select")}} and {{HTMLElement("textarea")}} form control elements. If present on any of these input types and elements, the {{cssxref(':required')}} pseudo class will match. If the attribute is not included, the {{cssxref(':optional')}} pseudo class will match.
The attribute is not supported on, or relevant to, {{HTMLElement("input/range","range")}} and {{HTMLElement("input/color","color")}} input types, as both have default values. Type color
defaults to #000000
. Type range
defaults to the midpoint between min
and max
— with min
and max
defaulting to 0 and 100 respectively in most browsers if not declared. required
is also not supported on the {{HTMLElement("input/hidden","hidden")}} input type — users cannot be expected to fill out a hidden form field. Finally, required
is not supported on any button input types, including {{HTMLElement("input/image","image")}}.
In the case of a same named group of {{HTMLElement("input/radio","radio")}} buttons, if a single radio button in the group has the required
attribute, a radio button in that group must be checked, although it doesn't have to be the one on which the attribute is applied. To improve code maintenance, it is recommended to either include the required
attribute in every same-named radio button in the group, or else in none.
In the case of a same named group of {{HTMLElement("input/checkbox","checkbox")}} input types, only the checkboxes with the required
attribute are required.
[!NOTE] Setting
aria-required="true"
tells a screen reader that an element (any element) is required, but has no bearing on the optionality of the element.
Attribute interactions
Because a read-only field cannot be changed, required
does not have any effect on inputs with the readonly
attribute also specified.
Usability
When including the required
attribute, provide a visible indication near the control informing the user that the , {{HTMLElement("select")}} or {{HTMLElement("textarea")}} is required. In addition, target required form controls with the {{cssxref(':required')}} pseudo-class, styling them in a way to indicate they are required. This improves usability for sighted users. Assistive technology should inform the user that the form control is mandatory based on the required attribute, but adding aria-required="true"
doesn't hurt, in case the browser / screen reader combination does not support required
yet.
Constraint validation
If the element is required and the element's value is the empty string, then the element is suffering from {{domxref('ValidityState.valueMissing','valueMissing')}} and the element will match the {{cssxref(':invalid')}} pseudo class.
Accessibility concerns
Provide an indication to users informing them the form control is required. Ensure the messaging is multi-faceted, such as through text, color, markings, and attribute, so that all users understand the requirements whether they have color blindness, cognitive differences, or are using a screen reader.
Example
HTML
<form>
<div class="group">
<input type="text" />
<label>Normal</label>
</div>
<div class="group">
<input type="text" required />
<label>Required</label>
</div>
<input type="submit" />
</form>
Result
{{EmbedLiveSample('Example')}}
Specifications
Browser compatibility
See also
- {{domxref('validityState.valueMissing')}}
- {{cssxref(':required')}} and {{cssxref(':optional')}}
- {{htmlelement('input')}}
- {{htmlelement('select')}}