<div id="pageData-name" class="pageData">Packaging</div>
<div id="pageData-showTOC" class="pageData">true</div>

<p>
This page describes how to package your extension.
As the <a href="overview.html">Overview</a> explains,
extensions are packaged as signed ZIP files
with the file extension "crx" &mdash;
for example, <code>myextension.crx</code>.
</p>

<p>
<b>Note:</b>
You might not need to package your extension.
If you publish your extension using the
<a href="https://chrome.google.com/webstore/developer/dashboard">Chrome Developer Dashboard</a>,
then the only reason to create your own <code>.crx</code> file
would be to distribute a non-public version &mdash;
for example, to alpha testers.
</p>

<!-- [PENDING: Refer to instructions on submitting an extension for inclusion in the gallery.] -->

<p>
When you package an extension,
the extension is assigned a unique key pair.
The public key is used as the identifier for the extension.
The private key is kept private
and used to sign each version of the extension.
</p>


<h2>Creating a package</h2>

<p>To package an extension:</p>
<ol>
  <li>
    Bring up the Extensions management page
    by going to this URL:
    <blockquote>
    <b>chrome://extensions</b>
    </blockquote>
  </li>

  <li>
    If <b>Developer mode</b> has a + by it,
    click the +.
  </li>

  <li>
    Click the <b>Pack extension</b> button.
    A dialog appears.
  </li>

  <li>
    In the <b>Extension root directory</b> field,
    specify the path to the extension's folder &mdash;
    for example, <code>c:\myext</code>.
    (Ignore the other field;
    you don't specify a private key file
    the first time you package a particular extension.)
  </li>

  <li>
    Click <b>OK</b>.
    The packager creates two files:
    a <code>.crx</code> file,
    which is the actual extension that can be installed,
    and a <code>.pem</code> file,
    which contains the private key.
  </li>
</ol>


<p>
<b>Do not lose the private key!</b>
Keep the <code>.pem</code> file secret and in a safe place.
You'll need it later if you want to do any of the following:
</p>
<ul>
<li><a href="#update">Update</a> the extension</li>
<li>Upload the extension using the
<a href="https://chrome.google.com/webstore/developer/dashboard">Chrome Developer Dashboard</a></li>
</ul>

<p>
If the extension is successfully packaged, you'll see a dialog like this
that tells you where to find
the <code>.crx</code> and <code>.pem</code> files:</p>
</p>

<img src="images/package-success.gif"
  width="554" height="208" />


<h2 id="update">Updating a package</h2>

<p>To create an updated version of your extension:</p>
<ol>
  <li>
    Increase the version number in <code>manifest.json</code>.
  </li>

  <li>
    Bring up the Extensions management page
    by going to this URL: <b>chrome://extensions</b>
  </li>

  <li>
    Click the <b>Pack extension</b> button.
    A dialog appears.
  </li>

  <li>
    In the <b>Extension root directory</b> field,
    specify the path to the extension's folder &mdash;
    for example, <code>c:\myext</code>.
  </li>

  <li>
    In the <b>Private key file</b> field,
    specify the location of the
    already generated <code>.pem</code> file for this extension &mdash;
    for example, <code>c:\myext.pem</code>.
  </li>

  <li>
    Click <b>OK</b>.
  </li>
</ol>

<p>If the updated extension is successfully packaged, you'll see a dialog like this:</p>

<img src="images/update-success.gif"
  width="298" height="160" />

<h2>Packaging at the command line</h2>

<p>
Another way to package extensions
is by invoking <code>chrome.exe</code> at the command line.
Use the <code>--pack-extension</code> flag
to specify the location of the extension's folder.
Use <code>--pack-extension-key</code>
to specify the location of the extension's private key file.
For example:
</p>

<pre>
chrome.exe --pack-extension=c:\myext --pack-extension-key=c:\myext.pem
</pre>

<p>
To suppress the dialog,
add <code>--no-message-box</code> to the command.
</p>

<h2>Package format and scripts</h2>
<p>
For more information on the format, as well as pointers to scripts you can use
to create <code>.crx</code> files, see <a href="crx.html">CRX package format</a>.
</p>