<h1>–<h6>：HTML 区域标题元素

HTML <h1>–<h6> 标题(Heading)元素呈现了六个不同的级别的标题，<h1> 级别最高，而 <h6> 级别最低。

The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.

该元素包含所有全局特性。

• 用户代理可以使用标题信息，例如自动构建文档的目录。
• 不要为了减小标题的字体而使用低级别的标题， 而是使用 CSS font-size 属性。
• 避免跳过某级标题：始终要从 <h1> 开始，接下来依次使用 <h2> 等等。
• 使用 <section> 元素时，为了方便起见，你应该考虑避免在同一个页面上重复使用 <h1>，<h1> 应被用于表示页面的标题，其他的标题当从 <h2> 开始。在使用 section 时，应当为每个 section 都使用一个 <h2>。详情请参考 Defining sections (en-US) in [Page not yet written] (en-US)。

下面的代码展示了所有可用的标题级别。

<h1>一级标题</h1>
<h2>二级标题</h2>
<h3>三级标题</h3>
<h4>四级标题</h4>
<h5>五级标题</h5>
<h6>六级标题</h6>

下面是这些代码的结果：

下面的代码展示了几个具有部分内容的标题。

<h1>Heading elements</h1>
<h2>Summary</h2>
<p>Some text here...</p>

<h2>Examples</h2>
<h3>Example 1</h3>
<p>Some text here...</p>

<h3>Example 2</h3>
<p>Some text here...</p>

<h2>See also</h2>
<p>Some text here...</p>

下面是代码的运行结果：

A common navigation technique for users of screen reading software is jumping from heading to heading to quickly determine the content of the page. Because of this, it is important to not skip one or more heading levels. Doing so may create confusion, as the person navigating this way may be left wondering where the missing heading is.

错误用法

<h1>Heading level 1</h1>
<h3>Heading level 3</h3>
<h4>Heading level 4</h4>

正确用法

<h1>Heading level 1</h1>
<h2>Heading level 2</h2>
<h3>Heading level 3</h3>

嵌套

Headings may be nested as subsections to reflect the organization of the content of the page. Most screen readers can also generate an ordered list of all the headings on a page, which can help a person quickly determine the hierarchy of the content:

1. h1 Beetles
   1. h2 Etymology
   2. h2 Distribution and Diversity
   3. h2 Evolution
      1. h3 Late Paleozoic
      2. h3 Jurassic
      3. h3 Cretaceous
      4. h3 Cenozoic
   4. h2 External Morphology
      1. h3 Head
         1. h4 Mouthparts
      2. h3 Thorax
         1. h4 Prothorax
         2. h4 Pterothorax
      3. h3 Legs
      4. h3 Wings
      5. h3 Abdomen

When headings are nested, heading levels may be "skipped" when closing a subsection.

• Headings • Page Structure • WAI Web Accessibility Tutorials
• MDN Understanding WCAG, Guideline 1.3 explanations
• Understanding Success Criterion 1.3.1 | W3C Understanding WCAG 2.0
• MDN Understanding WCAG, Guideline 2.4 explanations
• Understanding Success Criterion 2.4.1 | W3C Understanding WCAG 2.0
• Understanding Success Criterion 2.4.6 | W3C Understanding WCAG 2.0
• Understanding Success Criterion 2.4.10 | W3C Understanding WCAG 2.0

Another common navigation technique for users of screen reading software is to generate a list of sectioning content and use it to determine the page's layout.

Sectioning content can be labeled using a combination of the aria-labelledby and id attributes, with the label concisely describing the purpose of the section. This technique is useful for situations where there is more than one sectioning element on the same page.

示例

<header>
  <nav aria-labelledby="primary-navigation">
    <h2 id="primary-navigation">Primary navigation</h2>
    <!-- navigation items -->
  </nav>
</header>

<!-- page content -->

<footer>
  <nav aria-labelledby="footer-navigation">
    <h2 id="footer-navigation">Footer navigation</h2>
    <!-- navigation items -->
  </nav>
</footer>

In this example, screen reading technology would announce that there are two <nav> sections, one called "Primary navigation" and one called "Footer navigation". If labels were not provided, the person using screen reading software may have to investigate each nav element's contents to determine their purpose.

• Using the aria-labelledby attribute
• Labeling Regions • Page Structure • W3C WAI Web Accessibility Tutorials

• <p>
• <div>
• <section>