farinspace

HiFi is a head injection and foot injection plugin (or head include, foot include, head insert, foot insert, what ever you want to call it). It basically allows you to inject <code><script></code>, <code><style></code>, <code><meta></code> and any other code you want into the head and foot areas of your posts and pages. The code injected is page-specific, this means that only the pages you want code inserted into will be affected.
This plugin is most useful when you have specific functionality that needs to be added on a per-post/page basis.

HiFi (Head Injection, Foot Injection)

HiFi is a head and foot injection plugin. It allows you to inject code into the head and foot areas of your posts and pages on a per-page basis.

Joe Rhoney

average.technology

<blockquote>
Notice 
 Average is changing its name to AddFunc. Much better, huh?! Therefore, this plugin has been republished as <a href="https://wordpress.org/plugins/addfunc-head-footer-code/" rel="ugc">AddFunc Head & Footer Code</a>. The “AddFunc version” is compatible with the “Average version,” so installation and activation of either or both is risk-free. This also enables you to manually transfer all of your head and footer code to the “AddFunc version” (if you wish). The “Average version” will remain available with minimal support until it becomes a burden for AddFunc (probably for many years to come, as of 2014). Any new features will only be added to the “AddFunc version,” so it is of course the recommended version (at least for future projects). Thanks!
</blockquote>
Allows admins to add code to the <code><head></code> and/or footer of an individual post and/or site-wide. Ideal for scripts such as Google Analytics conversion tracking code and any other general or page-specific JavaScript.
Custom support tickets are available
See <a href="https://wordpress.org/plugins/average-head-footer-code/other_notes/" rel="ugc">Other Notes</a> tab for details.
<h3>Custom Support</h3>
If you have a custom support need, <a href="https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=7AF7P3TFKQ2C2" rel="nofollow ugc">please purchase your support ticket here</a>. Support tickets are responded to within 24 hours, but we answer them as soon as possible.
How it works
<ol>
<li><a href="https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=7AF7P3TFKQ2C2" rel="nofollow ugc">Purchase a support ticket via PayPal</a></li>
<li>You get a chance to provide the best way to contact you and a description of your need</li>
<li>I contact you as soon as I can (no less than 24 hours) and help resolve your issue</li>
</ol>
Note: This is for custom needs for help, not problems with the plugin, or instructions that should already be explain in the description. If you feel there are important details omitted from the description, installation steps, etc. of the plugin, please report them in the Support forum. Thanks!

Average Head & Footer Code

Easily add code to your head and/or footer, site-wide and/or on any individual page/post.

HiFi (Head Injection, Foot Injection) vs Average Head & Footer Code