Dave McHale

Contact Form 7 no longer supports the <code>on_sent_ok</code> and <code>on_submit</code> settings available on the Additional Settings screen as of version 5.0 of CF7. Both settings were deprecated before this release, which was why this plugin was first created. <a href="https://contactform7.com/additional-settings/" rel="nofollow ugc">https://contactform7.com/additional-settings/</a>
This plugin is meant to be a band-aid to quickly get your Additional Settings working. It reads the Additional Settings data and adds a javascript block when the form is output on the page, using DOM Events as suggested by the CF7 author. <a href="https://contactform7.com/dom-events/" rel="nofollow ugc">https://contactform7.com/dom-events/</a>

Contact Form 7: Support Deprecated Settings

Provide continued support for on_sent_ok and on_submit within Contact Form 7's Additional Settings

Frank Goossens

Optimizing Matters

EricJohnsonGuru

Eliminate Render-blocking Javascript in above-the-fold content with Async Javascript.
Render-blocking Javascript prevents above-the-fold content on your page from being rendered until the javascript has finished loading. This can impact on your page speed and ultimately your ranking within search engines. It can also impact your user’s experience.
Async JavaScript gives you full control of which scripts to add an ‘async’ or ‘defer’ attribute to or to exclude to help increase the performance of your WordPress website.

Async JavaScript

Plugin works as expected, settings are nice and minimal (using core styles) and there aren't any banners, notices or other marketing bloating things up.

Works great!

Async Javascript lets you add 'async' or 'defer' attribute to scripts to exclude to help increase the performance of your WordPres …

Contact Form 7: Support Deprecated Settings vs Async JavaScript