---
title: '::placeholder'
slug: 'Web/CSS/::placeholder'
translation_of: 'Web/CSS/::placeholder'
---
<div>{{CSSRef}}{{SeeCompatTable}}</div>

<p><a href="/en-US/docs/Web/CSS/Pseudo-elements">伪元素</a><strong><code>::placeholder</code></strong>可以选择一个表单元素的<a href="/en-US/docs/Web/HTML/Forms_in_HTML#The_placeholder_attribute">占位文本</a>,它允许开发者和设计师自定义<a href="/en-US/docs/Web/HTML/Forms_in_HTML#The_placeholder_attribute">占位文本</a>的样式。</p>

<pre class="brush: css no-line-numbers">::placeholder {
  color: red;
  font-size: 1.5em;
}</pre>

<p>在使用了<code>::placeholder</code>伪元素的选择器中,仅有小一部分CSS属性可以使用,这个集合可以参考{{cssxref("::first-line")}}伪元素。</p>

<h2 id="语法">语法</h2>

<pre class="brush: css">{{csssyntax}}
</pre>

<h2 id="示例">示例</h2>

<h3 id="红色文本">红色文本</h3>

<h4 id="HTML">HTML</h4>

<pre class="brush: html">&lt;input placeholder="我是红色的!"&gt;</pre>

<h4 id="CSS">CSS</h4>

<pre class="brush: css">input::placeholder {
  color: red;
  font-size: 1.2em;
  font-style: italic;
}</pre>

<h4 id="结果">结果</h4>

<p>{{ EmbedLiveSample('红色文本') }}</p>

<h3 id="绿色文本">绿色文本</h3>

<p> </p>

<h4 id="HTML_2">HTML</h4>

<pre class="brush: html">&lt;input placeholder="而我是绿色的!"&gt;</pre>

<h4 id="CSS_2">CSS</h4>

<pre class="brush: css">input::placeholder {
  color: green;
}</pre>

<h4 id="结果_2">结果</h4>

<p>{{EmbedLiveSample('绿色文本')}}</p>

<p> </p>

<h2 id="标准">标准</h2>

<table class="standard-table">
 <thead>
  <tr>
   <th scope="col">规范</th>
   <th scope="col">状态</th>
   <th scope="col">说明</th>
  </tr>
 </thead>
 <tbody>
  <tr>
   <td>{{SpecName('CSS4 Pseudo-Elements', '#placeholder-pseudo', '::placeholder')}}</td>
   <td>{{Spec2('CSS4 Pseudo-Elements')}}</td>
   <td>Initial definition</td>
  </tr>
 </tbody>
</table>

<h2 id="浏览器兼容性">浏览器兼容性</h2>

<p>{{CompatibilityTable}}</p>

<div id="compat-desktop">
<table class="compat-table">
 <tbody>
  <tr>
   <th>功能</th>
   <th>Chrome</th>
   <th>Firefox (Gecko)</th>
   <th>Edge</th>
   <th>Internet Explorer</th>
   <th>Opera</th>
   <th>Safari</th>
  </tr>
  <tr>
   <td>基本支持</td>
   <td>{{CompatChrome(57)}}</td>
   <td>{{CompatGeckoDesktop("51.0")}}<sup>[1]</sup></td>
   <td>{{CompatNo}}</td>
   <td>{{CompatNo}}</td>
   <td>44</td>
   <td>10.1</td>
  </tr>
  <tr>
   <td>前缀支持</td>
   <td>Supported</td>
   <td>Supported</td>
   <td>Supported</td>
   <td>10 -ms-</td>
   <td>Supported</td>
   <td>5 -webkit-</td>
  </tr>
 </tbody>
</table>
</div>

<div id="compat-mobile">
<table class="compat-table">
 <tbody>
  <tr>
   <th>功能</th>
   <th>Android</th>
   <th>Chrome for Android</th>
   <th>Firefox Mobile (Gecko)</th>
   <th>IE Mobile</th>
   <th>Opera Mobile</th>
   <th>Safari Mobile</th>
  </tr>
  <tr>
   <td>基本支持</td>
   <td>{{CompatChrome(57)}}</td>
   <td>{{CompatChrome(57)}}</td>
   <td>{{CompatGeckoMobile("52.0")}}</td>
   <td>{{CompatNo}}</td>
   <td> </td>
   <td>10.3</td>
  </tr>
  <tr>
   <td>前缀支持</td>
   <td>Supported</td>
   <td>Supported</td>
   <td>Supported</td>
   <td>10 -ms-</td>
   <td>Supported</td>
   <td>5 -webkit-</td>
  </tr>
 </tbody>
</table>
</div>

<p>[1] 在Gecko 51.0 {{geckoRelease("51.0")}} 以及更低的版本中,请使用 {{cssxref("::-moz-placeholder")}} 。</p>

<h2 id="相似阅读">相似阅读</h2>

<ul>
 <li>{{cssxref(":placeholder-shown")}}</li>
 <li>与此伪元素选择器功能相同的几个浏览器私有选择器:
  <ul>
   <li>{{cssxref("::-webkit-input-placeholder")}}</li>
   <li>{{cssxref("::-moz-placeholder")}}</li>
   <li>{{cssxref(":-ms-input-placeholder")}}</li>
  </ul>
 </li>
 <li><a href="/en-US/docs/Web/HTML/Forms_in_HTML">Forms in HTML</a></li>
 <li>{{HTMLElement("input")}}</li>
 <li>{{HTMLElement("textarea")}}</li>
</ul>