Attribute Reference

A scannable index of the HTML attributes you'll use most often—global attributes available on every element, plus the specialized ones for forms, media, links, and accessibility.

Global Attributes

These work on virtually every HTML element.

Attribute	Description
id	A unique identifier for the element within the document
class	One or more space-separated CSS class names
style	Inline CSS declarations, applied only to this element
title	Advisory text, usually shown as a tooltip on hover
lang	The natural language of the element's content
dir	Text direction: ltr, rtl, or auto
hidden	Removes the element from rendering and the accessibility tree
tabindex	Adds the element to (or removes it from) the keyboard tab order
contenteditable	Makes the element directly editable by the user
draggable	Enables the element to be dragged via the Drag and Drop API
spellcheck	Suggests whether the browser should spell-check the element's text
data-*	Custom attributes for storing element-specific data for scripting
accesskey	A single-key keyboard shortcut to focus/activate the element
translate	Hints to translation tools whether content should be translated

Form Attributes

Attribute	Applies to	Description
action	<form>	The URL the form data is submitted to
method	<form>	HTTP method for submission: get or post
enctype	<form>	Encoding for the submitted data, e.g. multipart/form-data for file uploads
novalidate	<form>	Disables native browser validation on submit
name	form controls	The key used when submitting this field's value
value	form controls	The control's current or default value
type	<input>, <button>	Selects the specific control variant
placeholder	text-like inputs	Faint hint text shown when the field is empty
required	form controls	Marks the field as mandatory for submission
disabled	form controls	Disables the control and excludes it from submission
readonly	text-like inputs	Prevents editing but still submits the field's value
checked	checkbox, radio	Marks a checkbox/radio as initially selected
multiple	file, select, email	Allows selecting/entering more than one value
min / max / step	number, range, date-like inputs	Bounds and increment for numeric/date inputs
pattern	text-like inputs	A regular expression the value must match
minlength / maxlength	text-like inputs	Minimum/maximum character count allowed
autocomplete	form, form controls	Hints the browser on autofill behavior
autofocus	one form control per page	Focuses the element automatically on page load
for	<label>	Associates the label with a control by matching id
form	form controls	Associates a control with a <form> elsewhere in the document

Media Attributes

Attribute	Applies to	Description
src	img, video, audio, iframe, script	The URL of the embedded resource
alt	img, area	Alternative text describing the image's content
width / height	img, video, iframe, canvas	Intrinsic dimensions; reserves layout space
loading	img, iframe	lazy defers off-screen loading; eager loads immediately
srcset	img, source	A set of image candidates at different resolutions/widths
sizes	img, source	Hints the rendered width of the image at various viewport sizes
controls	audio, video	Shows the browser's native playback UI
autoplay	audio, video	Starts playback automatically (often requires muted)
loop	audio, video	Restarts playback automatically when it ends
muted	audio, video	Mutes audio output by default
poster	video	An image shown before playback starts
preload	audio, video	Hints how much to buffer before playback: none, metadata, auto
fetchpriority	img, link, script	Hints the relative fetch priority of the resource
decoding	img	Hints whether image decoding may happen async or must be sync

Link Attributes

Attribute	Applies to	Description
href	a, link, area, base	The destination URL
target	a, form, iframe	Where to open the result: _blank, _self, _parent, _top
rel	a, link	Relationship between the current document and the target (e.g. nofollow, noopener)
download	a	Forces the browser to download the link's target instead of navigating
hreflang	a, link	The language of the linked resource
type	link, script, a	The MIME type of the linked/embedded resource
as	link (rel=preload)	The kind of resource being preloaded, for correct prioritization
crossorigin	link, script, img	Configures CORS behavior for the fetch
integrity	link, script	A subresource-integrity hash to verify fetched content
referrerpolicy	a, link, img, iframe	Controls how much referrer information is sent

ARIA Attributes Overview

ARIA (Accessible Rich Internet Applications) attributes supplement native HTML semantics for assistive technology. Prefer native elements first—reach for ARIA only when no native element covers the interaction.

Attribute	Description
role	Declares or overrides an element's accessibility role
aria-label	Supplies an accessible name when no visible text label exists
aria-labelledby	Points to another element (by id) that provides the accessible name
aria-describedby	Points to element(s) supplying additional descriptive text
aria-hidden	Hides an element (and its descendants) from the accessibility tree
aria-live	Marks a region whose content changes should be announced automatically
aria-expanded	Indicates whether a collapsible control is currently expanded
aria-checked	Indicates the checked state of a custom checkbox/radio/switch
aria-disabled	Indicates the element is perceivable but currently disabled
aria-invalid	Flags a form field as currently failing validation
aria-current	Marks the current item within a set (e.g. current page in nav)
aria-controls	Identifies the element(s) whose content this control affects
aria-haspopup	Indicates the element triggers a popup (menu, dialog, listbox)

Global attributes apply everywhere

Attributes like id, class, and data-* aren't restricted to any specific element—they're valid on virtually all of them, including semantic and form elements listed elsewhere on this page.