Chris J. Zähller

In its default settings, Contact Form 7 loads its JavaScript and CSS stylesheet on every page. This slows page loading and taxes server and client resources. Use this plugin to control which pages the scripts load on.
NEW in v1.0.15: The plugin also prevents scripts and styles from the following plugins from loading. If you are using any other plugin that extends Contact Form 7 and loads its scripts on all pages, please open a support ticket and we will look into adding it.
<ul>
<li>Contact Form 7 Conditional Fields</li>
<li>Contact Form 7 Multi-Step Forms</li>
<li>Contact Form CFDB7</li>
<li>Drag and Drop Multiple File Upload — Contact Form 7</li>
</ul>
<h3>Translations</h3>
<ul>
<li>English: Default language, always included</li>
</ul>
Would you like to help translate Conditionally Load CF7 into your own language? <a href="https://translate.wordpress.org/projects/wp-plugins/cf7-conditional-load" rel="nofollow ugc">You can do that here!</a>

Conditionally Load CF7

Load Contact Form 7 & select CF7-related plugin scripts & styles only where needed.

nigro.simone

This small plugin (2 Kb) moves JavaScript to the footer and improve page load times. 
Note: this only works if your other plugins and theme add the JavaScripts correctly.
Configurations are not required! You just have to install it and after the plugin does it all, none further action it’s required.

Speed Up – JavaScript To Footer

Move all the possible JavaScript files from head to footer and improve page load times.

Conditionally Load CF7 vs Speed Up – JavaScript To Footer