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---
title: Content-Encoding
slug: Web/HTTP/Заголовки/Content-Encoding
tags:
- Content-Encoding
- HTTP
- Headers
translation_of: Web/HTTP/Headers/Content-Encoding
---
<div>{{HTTPSidebar}}</div>
<p><strong><code>Content-Encoding</code></strong> - это сущность заголовка, используемая для сжатия медиа-типа. При наличии ее значение определяет кодировку, примененную к сущности <strong><code>body</code></strong>. Это позволяет клиенту информацию как декодировать <strong><code>body</code></strong>, чтобы получить медиа-тип ссылающийся на заголовок <code><strong>Content-Type </strong></code></p>
<p>Рекомендация - сжимать данные насколько это возможно и следовательно использовать это поле, но некоторые типы данных, такие как изображения в формате jpeg, уже сжаты. Иногда, использование дополнительного сжатия не уменьшает размер пакета и даже может сделать загрузку дольше.</p>
<table class="properties">
<tbody>
<tr>
<th scope="row">Header type</th>
<td>{{Glossary("Entity header")}}</td>
</tr>
<tr>
<th scope="row">{{Glossary("Forbidden header name")}}</th>
<td>no</td>
</tr>
</tbody>
</table>
<h2 id="Синтаксис">Синтаксис</h2>
<pre class="syntaxbox">Content-Encoding: gzip
Content-Encoding: compress
Content-Encoding: deflate
Content-Encoding: identity
Content-Encoding: br
// Multiple, in the order in which they were applied
Content-Encoding: gzip, identity
Content-Encoding: deflate, gzip
</pre>
<h2 id="Директивы">Директивы</h2>
<dl>
<dt><code>gzip</code></dt>
<dd>A format using the <a class="external" href="http://en.wikipedia.org/wiki/LZ77_and_LZ78#LZ77">Lempel-Ziv coding</a> (LZ77), with a 32-bit CRC. This is the original format of the UNIX <em>gzip</em> program. The HTTP/1.1 standard also recommends that the servers supporting this content-encoding should recognize <code>x-gzip</code> as an alias, for compatibility purposes.</dd>
<dt><code>compress</code></dt>
<dd>A format using the <a class="external" href="http://en.wikipedia.org/wiki/LZW">Lempel-Ziv-Welch</a> (LZW) algorithm. The value name was taken from the UNIX <em>compress</em> program, which implemented this algorithm. Like the compress program, which has disappeared from most UNIX distributions, this content-encoding is not used by many browsers today, partly because of a patent issue (it expired in 2003).</dd>
<dt><code>deflate</code></dt>
<dd>Using the <a class="external" href="http://en.wikipedia.org/wiki/Zlib">zlib</a> structure (defined in <a class="external" href="http://tools.ietf.org/html/rfc1950">RFC 1950</a>) with the <a class="external" href="http://en.wikipedia.org/wiki/DEFLATE"><em>deflate</em></a> compression algorithm (defined in <a class="external" href="http://tools.ietf.org/html/rfc1951">RFC 1951</a>).</dd>
<dt><code>identity</code></dt>
<dd>Indicates the identity function (i.e., no compression or modification). This token, except if explicitly specified, is always deemed acceptable.</dd>
<dt><code>br</code></dt>
<dd>A format using the <a href="https://en.wikipedia.org/wiki/Brotli">Brotli</a> algorithm.</dd>
</dl>
<h2 id="Examples">Examples</h2>
<h3 id="Compressing_with_gzip">Compressing with gzip</h3>
<p>On the client side, you can advertise a list of compression schemes that will be sent along in an HTTP request. The {{HTTPHeader("Accept-Encoding")}} header is used for negotiating content encoding.</p>
<pre>Accept-Encoding: gzip, deflate</pre>
<p>The server responds with the scheme used, indicated by the <code>Content-Encoding</code> response header.</p>
<pre>Content-Encoding: gzip</pre>
<p>Note that the server is not obligated to use any compression method. Compression highly depends on server settings and used server modules.</p>
<h2 id="Specifications">Specifications</h2>
<table class="standard-table">
<thead>
<tr>
<th scope="col">Specification</th>
<th scope="col">Title</th>
</tr>
</thead>
<tbody>
<tr>
<td>{{RFC("7932", "Brotli Compressed Data Format")}}</td>
<td>Brotli Compressed Data Format</td>
</tr>
<tr>
<td>{{RFC("7231", "Content-Encoding", "3.1.2.2")}}</td>
<td>Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content</td>
</tr>
<tr>
<td>{{RFC("2616", "Content-Encoding", "14.11")}}</td>
<td>Content-Encoding</td>
</tr>
</tbody>
</table>
<h2 id="Browser_compatibility">Browser compatibility</h2>
<p class="hidden">The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out <a href="https://github.com/mdn/browser-compat-data">https://github.com/mdn/browser-compat-data</a> and send us a pull request.</p>
<p>{{Compat("http.headers.Content-Encoding")}}</p>
<h2 id="See_also">See also</h2>
<ul>
<li>{{HTTPHeader("Accept-Encoding")}}</li>
<li>{{HTTPHeader("Transfer-Encoding")}}</li>
</ul>
|
