Hướng dẫn html attribute list


HTML attributes provide additional information about HTML elements.


HTML Attributes

  • All HTML elements can have attributes
  • Attributes provide additional information about elements
  • Attributes are always specified in the start tag
  • Attributes usually come in name/value pairs like: name="value"

The href Attribute

The tag defines a hyperlink. The href attribute specifies the URL of the page the link goes to:

You will learn more about links in our HTML Links chapter.


The src Attribute

The

Hướng dẫn html attribute list
.

Notes: External images might be under copyright. If you do not get permission to use it, you may be in violation of copyright laws. In addition, you cannot control external images; it can suddenly be removed or changed.

2. Relative URL - Links to an image that is hosted within the website. Here, the URL does not include the domain name. If the URL begins without a slash, it will be relative to the current page. Example: src="img_girl.jpg". If the URL begins with a slash, it will be relative to the domain. Example: src="/images/img_girl.jpg".

Tip: It is almost always best to use relative URLs. They will not break if you change domain.


The width and height Attributes

The

Hướng dẫn html attribute list

Try it Yourself »

You will learn more about images in our HTML Images chapter.



The style Attribute

The style attribute is used to add styles to an element, such as color, font, size, and more.

You will learn more about styles in our HTML Styles chapter.


The lang Attribute

You should always include the lang attribute inside the tag, to declare the language of the Web page. This is meant to assist search engines and browsers.

The following example specifies English as the language:




...

Country codes can also be added to the language code in the lang attribute. So, the first two characters define the language of the HTML page, and the last two characters define the country.

The following example specifies English as the language and United States as the country:




...

You can see all the language codes in our HTML Language Code Reference.


The title Attribute

The title attribute defines some extra information about an element.

The value of the title attribute will be displayed as a tooltip when you mouse over the element:


We Suggest: Always Use Lowercase Attributes

The HTML standard does not require lowercase attribute names.

The title attribute (and all other attributes) can be written with uppercase or lowercase like title or TITLE.

However, W3C recommends lowercase attributes in HTML, and demands lowercase attributes for stricter document types like XHTML.

At W3Schools we always use lowercase attribute names.


We Suggest: Always Quote Attribute Values

The HTML standard does not require quotes around attribute values.

However, W3C recommends quotes in HTML, and demands quotes for stricter document types like XHTML.

Good:

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Bad:

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Sometimes you have to use quotes. This example will not display the title attribute correctly, because it contains a space:

 At W3Schools we always use quotes around attribute values.


Single or Double Quotes?

Double quotes around attribute values are the most common in HTML, but single quotes can also be used.

In some situations, when the attribute value itself contains double quotes, it is necessary to use single quotes:

Or vice versa:


Chapter Summary


HTML Exercises

Test Yourself With Exercises

Exercise:

Add a "tooltip" to the paragraph below with the text "About W3Schools".

W3Schools is a web developer's site.

Start the Exercise


HTML Attribute Reference

A complete list of all attributes for each HTML element, is listed in our: HTML Attribute Reference.