Vladimir Prelovac

The Yahoo! Exceptional Performance team recommends <a href="http://developer.yahoo.com/performance/rules.html#js_bottom" rel="nofollow ugc">placing scripts at the bottom of your page</a> because of the way browsers download components.
“The problem caused by scripts is that they block parallel downloads. The HTTP/1.1 specification suggests that browsers download no more than two components in parallel per hostname. If you serve your images from multiple hostnames, you can get more than two downloads to occur in parallel. While a script is downloading, however, the browser won’t start any other downloads, even on different hostnames.
In some situations it’s not easy to move scripts to the bottom. If, for example, the script uses document.write to insert part of the page’s content, it can’t be moved lower in the page. There might also be scoping issues. In many cases, there are ways to workaround these situations.”
WordPress default behavior is to load javascript in the page.
This plugin will move all javascript code to the footer if the plugins have <a href="http://www.prelovac.com/vladimir/best-practice-for-adding-javascript-code-to-wordpress-plugin" rel="nofollow ugc">declared javascript properly</a>.
Plugin by <a href="http://www.prelovac.com/vladimir" rel="nofollow ugc">Vladimir Prelovac</a>. Looking for <a href="http://www.prelovac.com/vladimir/services" rel="nofollow ugc">WordPress Services</a>?
<h3>License</h3>
This file is part of Footer JavaScript.
Footer JavaScript is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
Footer JavaScript is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with Footer JavaScript. If not, see <a href="http://www.gnu.org/licenses/" rel="nofollow ugc">http://www.gnu.org/licenses/</a>.

JavaScript to Footer

I used and face some of bad experience with it 

Can't give perfect result

This plugin automatically moves JavaScript code to page footer, speeding up page loading time.

SOGO

Tested with Gutenberg
Create a simple way to add javascript code to individual page post or custom post type header and footer, 
for example: add conversion code to thank you pages 
add google re-marketing code to individual pages 
and much more… 
added in version 1.3 the option to add script \ style to all pages not only individual pages, 
 this will allow you to add Google re-marketing code to the entire site or Google Analytics 
 to use it goto “settings” – “Header Footer Settings”
New Features (version 3.0): 
Added option for terms / category pages
New Features (version 2.3): 
 Added support for WooCommerce shop page.
<ol>
<li>
we support now exclude individual pages form printing the header and footer scripts, this is supported by 2 checkboxes in each page\post 
buy check it the script will not be display on this page
</li>
<li>
we added support to limit the script only for certain post type \ page
</li>
</ol>
if you like it \ use it – please rate us.
usage: 
You need to paste the code with the script tag, for example: 
 you js code

SOGO Add Script to Individual Pages Header Footer

Simple plugin to add script to header and footer for individual pages & posts

JavaScript to Footer vs SOGO Add Script to Individual Pages Header Footer