The <input> element

The <input> element is so powerful because of its attributes; the type attribute, described with examples above, being the most important. Since every <input> element, regardless of type, is based on the HTMLInputElement interface, they technically share the exact same set of attributes. However, in reality, most attributes have an effect on only a specific subset of input types. In addition, the way some attributes impact an input depends on the input type, impacting different input types in different ways.

This section provides a table listing all the attributes with a brief description. This table is followed by a list describing each attribute in greater detail, along with which input types they are associated with. Those that are common to most or all input types are defined in greater detail below. Attributes that are unique to particular input types-or attributes which are common to all input types but have special behaviors when used on a given input type-are instead documented on those types' pages.

Attributes for the <input> element include the global HTML attributes and additionally:

A few additional non-standard attributes are listed following the descriptions of the standard attributes.

accept

Valid for the file input type only, the accept attribute defines which file types are selectable in a file upload control. See the file input type.

alt

Valid for the image button only, the alt attribute provides alternative text for the image, displaying the value of the attribute if the image src is missing or otherwise fails to load. See the image input type.

autocomplete

(Not a Boolean attribute!) The autocomplete attribute takes as its value a space-separated string that describes what, if any, type of autocomplete functionality the input should provide. A typical implementation of autocomplete recalls previous values entered in the same input field, but more complex forms of autocomplete can exist. For instance, a browser could integrate with a device's contacts list to autocomplete email addresses in an email input field. See autocomplete for permitted values.

The autocomplete attribute is valid on hidden, text, search, url, tel, email, date, month, week, time, datetime-local, number, range, color, and password. This attribute has no effect on input types that do not return numeric or text data, being valid for all input types except checkbox, radio, file, or any of the button types.

See the autocomplete attribute for additional information, including information on password security and how autocomplete is slightly different for hidden than for other input types.

autofocus

A Boolean attribute which, if present, indicates that the input should automatically have focus when the page has finished loading (or when the <dialog> containing the element has been displayed).

Note: An element with the autofocus attribute may gain focus before the DOMContentLoaded event is fired.

No more than one element in the document may have the autofocus attribute. If put on more than one element, the first one with the attribute receives focus.

The autofocus attribute cannot be used on inputs of type hidden, since hidden inputs cannot be focused.

Warning: Automatically focusing a form control can confuse visually-impaired people using screen-reading technology and people with cognitive impairments. When autofocus is assigned, screen-readers "teleport" their user to the form control without warning them beforehand.

Use careful consideration for accessibility when applying the autofocus attribute. Automatically focusing on a control can cause the page to scroll on load. The focus can also cause dynamic keyboards to display on some touch devices. While a screen reader will announce the label of the form control receiving focus, the screen reader will not announce anything before the label, and the sighted user on a small device will equally miss the context created by the preceding content.

capture

Introduced in the HTML Media Capture specification and valid for the file input type only, the capture attribute defines which media-microphone, video, or camera-should be used to capture a new file for upload with file upload control in supporting scenarios. See the file input type.

checked

Valid for both radio and checkbox types, checked is a Boolean attribute. If present on a radio type, it indicates that the radio button is the currently selected one in the group of same-named radio buttons. If present on a checkbox type, it indicates that the checkbox is checked by default (when the page loads). It does not indicate whether this checkbox is currently checked: if the checkbox's state is changed, this content attribute does not reflect the change. (Only the HTMLInputElement's checked IDL attribute is updated).

Note: Unlike other input controls, a checkboxes and radio buttons value are only included in the submitted data if they are currently checked. If they are, the name and the value(s) of the checked controls are submitted.

For example, if a checkbox whose name is fruit has a value of cherry, and the checkbox is checked, the form data submitted will include fruit=cherry. If the checkbox isn't active, it isn't listed in the form data at all. The default value for checkboxes and radio buttons is on.

dirname

Valid for text and search input types only, the dirname attribute enables the submission of the directionality of the element. When included, the form control will submit with two name/value pairs: the first being the name and value, the second being the value of the dirname as the name with the value of ltr or rtl being set by the browser.

The following non-standard attributes are also available on some browsers. As a general rule, you should avoid using them unless it can't be helped.

autocapitalize Non-standard

(Safari only). A string which indicates how auto-capitalization should be applied while the user is editing this field. Permitted values are:

none

Do not automatically capitalize any text

sentences

Automatically capitalize the first character of each sentence.

words

Automatically capitalize the first character of each word.

characters

Automatically capitalize every character.

autocorrect Non-standard

(Safari only). A string which indicates whether to activate automatic correction while the user is editing this field. Permitted values are:

on

Enable automatic correction of typos, as well as processing of text substitutions if any are configured.

off

Disable automatic correction and text substitutions.

incremental Non-standard

The Boolean attribute incremental is a WebKit and Blink extension (so supported by Safari, Opera, Chrome, etc.) which, if present, tells the user agent to process the input as a live search. As the user edits the value of the field, the user agent sends search events to the HTMLInputElement object representing the search box. This allows your code to update the search results in real time as the user edits the search.

If incremental is not specified, the search event is only sent when the user explicitly initiates a search (such as by pressing the Enter or Return key while editing the field).

The search event is rate-limited so that it is not sent more frequently than an implementation-defined interval.

orient Non-standard

Similar to the -moz-orient non-standard CSS property impacting the <progress> and <meter> elements, the orient attribute defines the orientation of the range slider. Values include horizontal, meaning the range is rendered horizontally, and vertical, where the range is rendered vertically.

results Non-standard

The results attribute-supported only by Safari-is a numeric value that lets you override the maximum number of entries to be displayed in the <input> element's natively-provided drop-down menu of previous search queries.

The value must be a non-negative decimal number. If not provided, or an invalid value is given, the browser's default maximum number of entries is used.

webkitdirectory Non-standard

The Boolean webkitdirectory attribute, if present, indicates that only directories should be available to be selected by the user in the file picker interface. See HTMLInputElement.webkitdirectory for additional details and examples.

Though originally implemented only for WebKit-based browsers, webkitdirectory is also usable in Microsoft Edge as well as Firefox 50 and later. However, even though it has relatively broad support, it is still not standard and should not be used unless you have no alternative.

The following methods are provided by the HTMLInputElement interface which represents <input> elements in the DOM. Also available are those methods specified by the parent interfaces, HTMLElement, Element, Node, and EventTarget.

checkValidity()

Returns true if the element's value passes validity checks; otherwise, returns false and fires an invalid event at the element.

reportValidity()

Returns true if the element's value passes validity checks; otherwise, returns false, fires an invalid event at the element, and (if the event isn't canceled) reports the problem to the user.

select()

Selects the entire content of the <input> element, if the element's content is selectable. For elements with no selectable text content (such as a visual color picker or calendar date input), this method does nothing.

setCustomValidity()

Sets a custom message to display if the input element's value isn't valid.

setRangeText()

Sets the contents of the specified range of characters in the input element to a given string. A selectMode parameter is available to allow controlling how the existing content is affected.

setSelectionRange()

Selects the specified range of characters within a textual input element. Does nothing for inputs which aren't presented as text input fields.

stepDown()

Decrements the value of a numeric input by one, by default, or by the specified number of units.

stepUp()

Increments the value of a numeric input by one or by the specified number of units.

By default, the appearance of placeholder text is a translucent or light gray. The ::placeholder pseudo-element is the input's placeholder text. It can be styled with a limited subset of CSS properties.

::placeholder {
  color: blue;
}

The appearance property enables the displaying of (almost) any element as a platform-native style based on the operating system's theme as well as the removal of any platform-native styling with the none value.

You could make a <div> look like a radio button with div {appearance: radio;} or a radio look like a checkbox with [type="radio"] {appearance: checkbox;}, but don't.

Setting appearance: none removes platform native borders, but not functionality.

A property specific to text entry-related elements is the CSS caret-color property, which lets you set the color used to draw the text input caret:

HTML

<label for="textInput">Note the red caret:</label>
<input id="textInput" class="custom" size="32" />

CSS

input.custom {
  caret-color: red;
  font:
    16px "Helvetica",
    "Arial",
    "sans-serif";
}

In certain cases (typically involving non-textual inputs and specialized interfaces), the <input> element is a replaced element. When it is, the position and size of the element's size and positioning within its frame can be adjusted using the CSS object-position and object-fit properties

Labels are needed to associate assistive text with an <input>. The <label> element provides explanatory information about a form field that is always appropriate (aside from any layout concerns you have). It's never a bad idea to use a <label> to explain what should be entered into an <input> or <textarea>.

Associated labels

The semantic pairing of <input> and <label> elements is useful for assistive technologies such as screen readers. By pairing them using the <label>'s for attribute, you bond the label to the input in a way that lets screen readers describe inputs to users more precisely.

It does not suffice to have plain text adjacent to the <input> element. Rather, usability and accessibility requires the inclusion of either implicit or explicit <label>:

<!-- inaccessible -->
<p>Enter your name: <input id="name" type="text" size="30" /></p>

<!-- implicit label -->
<p>
  <label>Enter your name: <input id="name" type="text" size="30" /></label>
</p>

<!-- explicit label -->
<p>
  <label for="name">Enter your name: </label>
  <input id="name" type="text" size="30" />
</p>

The first example is inaccessible: no relationship exists between the prompt and the <input> element.

In addition to an accessible name, the label provides a larger 'hit' area for mouse and touch screen users to click on or touch. By pairing a <label> with an <input>, clicking on either one will focus the <input>. If you use plain text to "label" your input, this won't happen. Having the prompt part of the activation area for the input is helpful for people with motor control conditions.

As web developers, it's important that we never assume that people will know all the things that we know. The diversity of people using the web-and by extension your website-practically guarantees that some of your site's visitors will have some variation in thought processes and/or circumstances that leads them to interpret your forms very differently from you without clear and properly-presented labels.

Placeholders are not accessible

The placeholder attribute lets you specify text that appears within the <input> element's content area itself when it is empty. The placeholder should never be required to understand your forms. It is not a label, and should not be used as a substitute, because it isn't. The placeholder is used to provide a hint as to what an inputted value should look like, not an explanation or prompt.

Not only is the placeholder not accessible to screen readers, but once the user enters any text into the form control, or if the form control already has a value, the placeholder disappears. Browsers with automatic page translation features may skip over attributes when translating, meaning the placeholder may not get translated.

Note: Don't use the placeholder attribute if you can avoid it. If you need to label an <input> element, use the <label> element.

Size

Interactive elements such as form input should provide an area large enough that it is easy to activate them. This helps a variety of people, including people with motor control issues and people using non-precise forms of input such as a stylus or fingers. A minimum interactive size of 44×44 CSS pixels is recommended.