WP-Validate indexes your site, collecting all the blog posts, pages and other published content, and submits it to the W3C’s HTML Validator, which then returns the response.
WP-Validate then lists the valid pages, and the invalid pages, with a link to the specific validator URL.

WP-Validate

WP-Validate collects all the pages on your site and runs them through the W3C's HTML Validator.

Sumit Malviya

The W3C Type Attribute Warnings Removal plugin is a valuable tool for WordPress users aiming to optimize their website’s SEO performance and adhere to web standards set by the World Wide Web Consortium (W3C). This plugin specifically targets and removes unnecessary type attributes from script and style tags generated by WordPress, thereby addressing potential validation issues highlighted by the W3C validator tool.
Maintaining a compliant website is crucial for SEO success, and this plugin simplifies the process by automatically eliminating type attribute warnings, enhancing your site’s overall quality and performance. By ensuring conformity with W3C standards, you not only improve search engine visibility but also enhance accessibility and user experience.
The Plugin Removes the below warnings from the website.
The type attribute is unnecessary for JavaScript resources.
The type attribute for the style element is not needed and should be ommited.
Introducing the <a href="https://saasycodes.com/product/cleanser-w3c-markup-validator/" rel="nofollow ugc">Cleanser W3C Markup Validator Pro</a> Plugin: 
The “Cleanser W3C Markup Validator” plugin addresses a specific challenge encountered during the W3C validation process. Often, website owners and developers encounter warnings related to the “type” attribute in HTML elements, which may not necessarily impact the website’s functionality or user experience.
What you will get in the <a href="https://saasycodes.com/product/cleanser-w3c-markup-validator/" rel="nofollow ugc">Pro version</a>
<ol>
<li>Generates complete report of errors/warnings of all pages</li>
<li>Automatically corrects most commonally occured errors</li>
<li>Option to find and edit page to correct errors.</li>
<li>Improve SEO performance through W3C compliance</li>
</ol>

Type Attribute Warnings Removal

It removes automatically type attributes from website after installing it.

Good Plugin

Remove type attribute from script and style tags added by WordPress

WP-Validate vs Type Attribute Warnings Removal