HTML attribute: required #
::: section-content
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
text
,
search
,
url
,
tel
,
email
,
password
,
date
,
month
,
week
,
time
,
datetime-local
,
number
,
checkbox
,
radio
,
file
,
<input>
types along with the
<select>
and
<textarea>
form control elements. If present on any of these input types and
elements, the
:required
pseudo class will match. If the attribute is not included, the
:optional
pseudo class will match.
The attribute is not supported or relevant to
range and
color, as
both have default values. It is also not supported on
hidden as it can not be expected that a user
to fill out a form that is hidden. Nor is it supported on any of the
button types, including image
.
Note color
and range
don't support required
as both always have a
value. Type color
defaults to #000000
. The default for range
is
the midpoint between min
and max
— with min
and max
defaulting
to 0 and 100 respectively in most browsers if not declared.
In the case of a same named group of
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
checkbox input types, only the checkboxes
with the required
attribute are required.
::: {#sect1 .notecard .note}
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 #
::: section-content
Because a read-only field cannot have a value, required
does not have
any effect on inputs with the
readonly
attribute also
specified.
:::
Usability #
::: section-content
When including the required
attribute, provide a visible indication
near the control informing the user that the
<input>
,
<select>
or
<textarea>
is required. In addition, target
required form controls with the
: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 #
::: section-content
If the element is required and the element's value is the empty string,
then the element is suffering from
valueMissing
and the element will match the
:invalid
pseudo class.
:::
Accessibility concerns #
::: section-content 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 #
::: section-content ::: code-example [html]{.language-name}
<form>
<div class="group">
<input type="text" />
<label>Normal</label>
<div class="group">
<input type="text" required />
<label>Required</label>
<input type="submit" />
</form>
::: :::
Result #
::: section-content ::: {#sect2 .code-example} ::: iframe ::: ::: :::
Specifications #
::: {.notecard .warning} No specification found
No specification data found for html.elements.attributes.required
.
Check for problems with this page or contribute a missing
spec_url
to
mdn/browser-compat-data.
Also make sure the specification is included in
w3c/browser-specs.
:::
Browser compatibility #
See also #
::: section-content
::: _attribution
© 2005–2023 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5
or later.
https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/required{._attribution-link}
:::