---
title: StorageEstimate
slug: Web/API/StorageEstimate
translation_of: Web/API/StorageEstimate
---
<div>{{securecontext_header}}{{APIRef("Storage")}}</div>

<div> </div>

<p><strong><code>StorageEstimate</code></strong> 提供对你的域名或Web app的数据存储空间总量和已用量的估计值,该对象实例由{{domxref("StorageManager")}}的{{domxref("StorageManager.estimate", "estimate()")}} 方法返回的{{jsxref("Promise")}}返回.</p>

<p>这些值仅为估计值有多种原因,既有对性能的考虑,也有防止将其作为指纹(fingerprinting)的目的.详情请参看属性.</p>

<h2 id="属性">属性</h2>

<p><em>该对象目前总是同时包含以下两个属性.</em></p>

<dl>
 <dt>{{domxref("StorageEstimate.quota", "quota")}} {{securecontext_inline}}</dt>
 <dd>用户设备为你的域名或Web app预留的存储空间总大小,且该大小为估计值.虽然实际上可能有比这更多的存储空间,但这时你不应使用那多余的部分.</dd>
 <dt>{{domxref("StorageEstimate.usage", "usage")}} {{securecontext_inline}}</dt>
 <dd>你的域名或Web app已经使用的存储空间大小,且该大小为估计值.剩余可用空间请综合quota属性计算.</dd>
</dl>

<h2 id="规范">规范</h2>

<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
  <tr>
   <td>{{SpecName('Storage', '#dictdef-storageestimate', 'StorageEstimate')}}</td>
   <td>{{Spec2('Storage')}}</td>
   <td>Initial definition.</td>
  </tr>
 </tbody>
</table>

<h2 id="浏览器兼容性">浏览器兼容性</h2>

<div>{{CompatibilityTable}}</div>

<div id="compat-desktop">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Chrome</th>
   <th>Firefox (Gecko)</th>
   <th>Internet Explorer</th>
   <th>Microsoft Edge</th>
   <th>Opera</th>
   <th>Safari (WebKit)</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>{{CompatChrome(55)}}</td>
   <td>{{CompatGeckoDesktop(57)}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatOpera(42)}}</td>
   <td>{{CompatUnknown}}</td>
  </tr>
 </tbody>
</table>
</div>

<div id="compat-mobile">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Android Webview</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>Basic support</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatChrome(55)}}</td>
   <td>{{ CompatGeckoMobile(57)}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatOperaMobile(42)}}</td>
   <td>{{CompatUnknown}}</td>
  </tr>
 </tbody>
</table>
</div>

<h2 id="相关链接">相关链接</h2>

<ul>
 <li><a href="/en-US/docs/Web/API/Storage_API">Storage API</a></li>
 <li>{{domxref("StorageManager")}}</li>
 <li>{{domxref("StorageManager.estimate()")}}</li>
 <li>{{domxref("NavigatorStorage.storage", "navigator.storage")}}</li>
</ul>