butterfly/kb
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
bfa66fc0f8
kb/data/developer.mozilla.org/en-US/docs/Glossary/Attribute-0.md

195 lines
12 KiB
Markdown
Raw Blame History

---
title: "Attribute - Glossary | MDN"
chunk: 1/3
source: "https://developer.mozilla.org/en-US/docs/Glossary/Attribute"
category: "reference"
tags: "web, html, css, javascript, documentation"
date_saved: "2026-05-05T05:24:35.238959+00:00"
instance: "kb-cron"
---
* [Skip to main content](https://developer.mozilla.org/en-US/docs/Glossary/Attribute#content)
* [Skip to search](https://developer.mozilla.org/en-US/docs/Glossary/Attribute#search)
[ MDN ](https://developer.mozilla.org/en-US/)
HTML
[HTML: Markup language](https://developer.mozilla.org/en-US/docs/Web/HTML)
HTML reference
* [Elements](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements)
* [Global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes)
* [Attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes)
* [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference "See all HTML references")
HTML guides
* [Responsive images](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Responsive_images)
* [HTML cheatsheet](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Cheatsheet)
* [Date & time formats](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides/Date_and_time_formats)
* [See all…](https://developer.mozilla.org/en-US/docs/Web/HTML/Guides "See all HTML guides")
Markup languages
* [SVG](https://developer.mozilla.org/en-US/docs/Web/SVG)
* [MathML](https://developer.mozilla.org/en-US/docs/Web/MathML)
* [XML](https://developer.mozilla.org/en-US/docs/Web/XML)
CSS
[CSS: Styling language](https://developer.mozilla.org/en-US/docs/Web/CSS)
CSS reference
* [Properties](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Properties)
* [Selectors](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors)
* [At-rules](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/At-rules)
* [Values](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Values)
* [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Reference "See all CSS references")
CSS guides
* [Box model](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Box_model/Introduction)
* [Animations](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Animations/Using)
* [Flexbox](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Flexible_box_layout/Basic_concepts)
* [Colors](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Applying_color)
* [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides "See all CSS guides")
Layout cookbook
* [Column layouts](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Column_layouts)
* [Centering an element](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Center_an_element)
* [Card component](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook/Card)
* [See all…](https://developer.mozilla.org/en-US/docs/Web/CSS/How_to/Layout_cookbook)
JavaScriptJS
[JavaScript: Scripting language](https://developer.mozilla.org/en-US/docs/Web/JavaScript)
JS reference
* [Standard built-in objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects)
* [Expressions & operators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators)
* [Statements & declarations](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements)
* [Functions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions)
* [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference "See all JavaScript references")
JS guides
* [Control flow & error handing](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Control_flow_and_error_handling)
* [Loops and iteration](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Loops_and_iteration)
* [Working with objects](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Working_with_objects)
* [Using classes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Using_classes)
* [See all…](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide "See all JavaScript guides")
Web APIs
[Web APIs: Programming interfaces](https://developer.mozilla.org/en-US/docs/Web/API)
Web API reference
* [File system API](https://developer.mozilla.org/en-US/docs/Web/API/File_System_API)
* [Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API)
* [Geolocation API](https://developer.mozilla.org/en-US/docs/Web/API/Geolocation_API)
* [HTML DOM API](https://developer.mozilla.org/en-US/docs/Web/API/HTML_DOM_API)
* [Push API](https://developer.mozilla.org/en-US/docs/Web/API/Push_API)
* [Service worker API](https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API)
* [See all…](https://developer.mozilla.org/en-US/docs/Web/API "See all Web API guides")
Web API guides
* [Using the Web animation API](https://developer.mozilla.org/en-US/docs/Web/API/Web_Animations_API/Using_the_Web_Animations_API)
* [Using the Fetch API](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch)
* [Working with the History API](https://developer.mozilla.org/en-US/docs/Web/API/History_API/Working_with_the_History_API)
* [Using the Web speech API](https://developer.mozilla.org/en-US/docs/Web/API/Web_Speech_API/Using_the_Web_Speech_API)
* [Using web workers](https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API/Using_web_workers)
All
[All web technology](https://developer.mozilla.org/en-US/docs/Web)
Technologies
* [Accessibility](https://developer.mozilla.org/en-US/docs/Web/Accessibility)
* [HTTP](https://developer.mozilla.org/en-US/docs/Web/HTTP)
* [URI](https://developer.mozilla.org/en-US/docs/Web/URI)
* [Web extensions](https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions)
* [WebAssembly](https://developer.mozilla.org/en-US/docs/WebAssembly)
* [WebDriver](https://developer.mozilla.org/en-US/docs/Web/WebDriver)
* [See all…](https://developer.mozilla.org/en-US/docs/Web "See all web technology references")
Topics
* [Media](https://developer.mozilla.org/en-US/docs/Web/Media)
* [Performance](https://developer.mozilla.org/en-US/docs/Web/Performance)
* [Privacy](https://developer.mozilla.org/en-US/docs/Web/Privacy)
* [Security](https://developer.mozilla.org/en-US/docs/Web/Security)
* [Progressive web apps](https://developer.mozilla.org/en-US/docs/Web/Progressive_web_apps)
Learn
[Learn web development](https://developer.mozilla.org/en-US/docs/Learn_web_development)
Frontend developer course
* [Getting started modules](https://developer.mozilla.org/en-US/docs/Learn_web_development/Getting_started)
* [Core modules](https://developer.mozilla.org/en-US/docs/Learn_web_development/Core)
* [MDN Curriculum](https://developer.mozilla.org/en-US/curriculum/)
* [Check out the video course from Scrimba, our partner](https://scrimba.com/frontend-path-c0j?via=mdn-learn-navbar)
Learn HTML
* [Structuring content with HTML module](https://developer.mozilla.org/en-US/docs/Learn_web_development/Core/Structuring_content)
Learn CSS
* [CSS styling basics module](https://developer.mozilla.org/en-US/docs/Learn_web_development/Core/Styling_basics)
* [CSS layout module](https://developer.mozilla.org/en-US/docs/Learn_web_development/Core/CSS_layout)
Learn JavaScript
* [Dynamic scripting with JavaScript module](https://developer.mozilla.org/en-US/docs/Learn_web_development/Core/Scripting)
Tools
Discover our tools
* [Playground](https://developer.mozilla.org/en-US/play)
* [HTTP Observatory](https://developer.mozilla.org/en-US/observatory)
* [Border-image generator](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Backgrounds_and_borders/Border-image_generator)
* [Border-radius generator](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Backgrounds_and_borders/Border-radius_generator)
* [Box-shadow generator](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Backgrounds_and_borders/Box-shadow_generator)
* [Color format converter](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Color_format_converter)
* [Color mixer](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Colors/Color_mixer)
* [Shape generator](https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Shapes/Shape_generator)
About
Get to know MDN better
* [About MDN](https://developer.mozilla.org/en-US/about)
* [Advertise with us](https://developer.mozilla.org/en-US/advertising)
* [Community](https://developer.mozilla.org/en-US/community)
* [MDN on GitHub](https://github.com/mdn)
[Blog](https://developer.mozilla.org/en-US/blog/)
1. [Glossary](https://developer.mozilla.org/en-US/docs/Glossary)
2. [Attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute)
# Attribute
An **attribute** extends an [HTML](https://developer.mozilla.org/en-US/docs/Glossary/HTML) or [XML](https://developer.mozilla.org/en-US/docs/Glossary/XML) [element](https://developer.mozilla.org/en-US/docs/Glossary/Element), changing its behavior or providing metadata.
An attribute always has the form `name="value"` (the attribute's identifier followed by its associated value). You may see attributes without an equals sign or a value. That is a shorthand for providing the empty string in HTML. However, this is not valid in XML: XML requires all attributes to have an explicit value.
A number of HTML attributes are [boolean attributes](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML). These attributes' values are only controlled by the presence or absence of the attribute. See [boolean attributes](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML) for more information.
## In this article
* [Reflection of an attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute#reflection_of_an_attribute)
* [See also](https://developer.mozilla.org/en-US/docs/Glossary/Attribute#see_also)
## [Reflection of an attribute](https://developer.mozilla.org/en-US/docs/Glossary/Attribute#reflection_of_an_attribute)
Attributes may be _reflected_ into a particular property of the specific interface.
This means that the value of the attribute can be read or written directly in JavaScript through a property on the corresponding interface, and vice versa. The reflected properties offer a more natural programming approach than getting and setting attributes using the [`getAttribute()`](https://developer.mozilla.org/en-US/docs/Web/API/Element/getAttribute "getAttribute\(\)") and [`setAttribute()`](https://developer.mozilla.org/en-US/docs/Web/API/Element/setAttribute "setAttribute\(\)") methods of the [`Element`](https://developer.mozilla.org/en-US/docs/Web/API/Element) interface.
For more information see [Attribute reflection](https://developer.mozilla.org/en-US/docs/Web/API/Document_Object_Model/Reflected_attributes).
## [See also](https://developer.mozilla.org/en-US/docs/Glossary/Attribute#see_also)
* [HTML attribute reference](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes)
* [Attribute reflection](https://developer.mozilla.org/en-US/docs/Web/API/Document_Object_Model/Reflected_attributes)
* Information about HTML's [global attributes](https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Global_attributes)
* XML StartTag Attribute Recommendation in [W3C XML Recommendation](https://www.w3.org/TR/xml/#sec-starttags)
* Related glossary terms:
* [Element](https://developer.mozilla.org/en-US/docs/Glossary/Element)
* [Tag](https://developer.mozilla.org/en-US/docs/Glossary/Tag)
* [HTML](https://developer.mozilla.org/en-US/docs/Glossary/HTML)
* [XML](https://developer.mozilla.org/en-US/docs/Glossary/XML)
* [Boolean attributes](https://developer.mozilla.org/en-US/docs/Glossary/Boolean/HTML)
* [Enumerated attributes](https://developer.mozilla.org/en-US/docs/Glossary/Enumerated)
Reference in New Issue View Git Blame Copy Permalink