Revision 1076174 of File

<div>{{APIRef}}</div>

<p>The <strong><code>File</code></strong> interface provides information about files and allows JavaScript in a web page to access their content.</p>

<p><code>File</code> objects are generally retrieved from a {{domxref("FileList")}} object returned as a result of a user selecting files using the&nbsp;{{HTMLElement("input")}}&nbsp;element, from a drag and drop operation's {{domxref("DataTransfer")}} object, or from the&nbsp;<code>mozGetAsFile()</code>&nbsp;API on an&nbsp;{{domxref("HTMLCanvasElement")}}. In Gecko, privileged code can create <code>File</code> objects representing any local file without user interaction (see {{anch("Gecko notes")}} for more information.)</p>

<p>A <code>File</code> object is specific kind of a {{domxref("Blob")}}, and can be used in any context that a Blob can. In particular, {{domxref("FileReader")}}, {{domxref("URL.createObjectURL()")}}, {{domxref("ImageBitmapFactories.createImageBitmap()", "createImageBitmap()")}}, and {{domxref("XMLHttpRequest", "", "send()")}} accept both <code>Blob</code>s and <code>File</code>s.</p>

<p>See <a href="/en-US/docs/Using_files_from_web_applications">Using files from web applications</a> for more information and examples.</p>

<h2 id="Properties">Properties</h2>

<p><em>The <code>File</code> interface also inherits properties from the {{domxref("Blob")}} interface:</em></p>

<dl>
 <dt>{{domxref("File.lastModified")}} {{readonlyinline}}</dt>
 <dd>Returns the last modified time sinch the UNIX epoch.</dd>
 <dt>{{domxref("File.lastModifiedDate")}} {{readonlyinline}} {{deprecated_inline}} {{gecko_minversion_inline("15.0")}}</dt>
 <dd>Returns the last modified <code><a href="/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date">Date</a></code> of the file referenced by the <code>File</code> object.</dd>
 <dt>{{domxref("File.name")}} {{readonlyinline}}</dt>
 <dd>Returns the name of the file referenced by the <code>File</code> object.</dd>
 <dt>{{domxref("File.webkitRelativePath")}}&nbsp;{{readonlyinline}} {{non-standard_inline}}</dt>
 <dd>Returns the path the URL of the {{domxref("File")}} is relative to.</dd>
</dl>

<h2 id="Methods">Methods</h2>

<p><em>The <code>File</code> interface doesn't define any methods, but inherits methods from the {{domxref("Blob")}} interface:</em></p>

<h2 id="Specifications">Specifications</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('File API')}}</td>
   <td>{{Spec2('File API')}}</td>
   <td>Initial definition</td>
  </tr>
 </tbody>
</table>

<h2 id="Browser_compatibility">Browser compatibility</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>Opera</th>
   <th>Safari (WebKit)</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>13</td>
   <td>{{CompatGeckoDesktop("1.9")}}<sup>[1]</sup><br />
    {{CompatGeckoDesktop("7")}}</td>
   <td>10.0</td>
   <td>11.5</td>
   <td>6.0</td>
  </tr>
  <tr>
   <td><code>name</code></td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatGeckoDesktop("1.9.2")}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
  </tr>
  <tr>
   <td><code>lastModifiedData</code> {{deprecated_inline}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatGeckoDesktop("15")}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
  </tr>
  <tr>
   <td><code>webkitRelativePath</code> {{non-standard_inline}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatGeckoDesktop("49")}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
  </tr>
 </tbody>
</table>
</div>

<div id="compat-mobile">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Android</th>
   <th>Firefox Mobile (Gecko)</th>
   <th>IE Phone</th>
   <th>Opera Mobile</th>
   <th>Safari Mobile</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatGeckoMobile("1.9")}}[1]<br />
    {{CompatGeckoMobile("7")}}</td>
   <td>{{CompatNo}}</td>
   <td>11.1</td>
   <td>6.0</td>
  </tr>
  <tr>
   <td><code>name</code></td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatGeckoMobile("1.9.2")}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
  </tr>
  <tr>
   <td><code>lastModifiedData</code> {{deprecated_inline}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatGeckoMobile("15")}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
  </tr>
  <tr>
   <td><code>webkitRelativePath</code> {{non-standard_inline}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatGeckoMobile("49")}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
  </tr>
 </tbody>
</table>
</div>

<p>[1] Non-standard implementation.</p>

<h3 id="Implementation_notes">Implementation notes</h3>

<ul>
 <li>In Gecko, you can use this API from within chrome code. See <a href="/en-US/docs/Extensions/Using_the_DOM_File_API_in_chrome_code">Using the DOM File API in chrome code</a> for details. To use it from chrome code, JSM and Bootstrap scope, you have to import it using <code><a href="/en-US/docs/Components.utils.importGlobalProperties">Cu.importGlobalProperties</a>(['File']);</code></li>
 <li>Starting from Gecko 6.0 {{geckoRelease("6.0")}}, privileged code (such as extensions) can pass an {{interface("nsIFile")}} object to the DOM <code>File</code> constructor to specify the file to reference.</li>
 <li>Starting from Gecko 8.0 {{geckoRelease("8.0")}}, you can use <code>new File</code> to create <code>File</code> objects from XPCOM component code instead of having to instantiate the {{interface("nsIDOMFile")}} object directly. The constructor takes, in contrast to {{domxref("Blob")}}, as second argument the filename. The filename can be any String.
  <pre class="syntaxbox">
new File(
&nbsp; Array parts,
&nbsp; String filename, 
  BlobPropertyBag properties
);</pre>
 </li>
 <li>The following non-standard properties and methods were removed in Gecko 7 {{geckoRelease("7.0")}}: {{domxref("File.fileName")}}, {{domxref("File.fileSize")}}, {{domxref("File.getAsBinary()")}}, {{domxref("File.getAsDataURL()")}}, {{domxref("File.getAsText()","File.getAsText(string encoding)")}} ({{bug("661876")}}). Standard properties {{domxref("File.name")}}, {{domxref("Blob.size")}}, and methods on {{domxref("FileReader")}} should be used instead.</li>
</ul>

<h2 id="See_also">See also</h2>

<ul>
 <li><a href="/en-US/docs/Using_files_from_web_applications">Using files from web applications</a></li>
 <li>{{domxref("FileReader")}}</li>
 <li><a href="/en-US/docs/Extensions/Using_the_DOM_File_API_in_chrome_code">Using the DOM File API in chrome code</a> (for privileged code running in Gecko, such as Firefox add-ons)</li>
</ul>