Jeff Starr

This plugin does one thing: disables the WP REST API for visitors who are not logged into WordPress. No configuration required.
This plugin works with only 22 short lines of code (less than 2KB). So it is super lightweight, fast, and effective.
Note: This plugin completely disables the WordPress REST API. So it is not recommended if you need the WP REST API for any functionality.
<h3>Features</h3>
<ul>
<li>Disable REST/JSON for visitors (not logged in)</li>
<li>Disables REST header in HTTP response for all users</li>
<li>Disables REST links in HTML head for all users</li>
<li>100% plug-and-play, set-it-and-forget solution</li>
</ul>
The fast, simple way to prevent abuse of your site’s REST/JSON API
How does it work? That depends on which version of WordPress you are using..
WordPress v4.7 and beyond
For WordPress 4.7 and better, this plugin completely disables the WP REST API unless the user is logged into WordPress.
<ul>
<li>For logged-in users, WP REST API works normally</li>
<li>For logged-out users, WP REST API is disabled</li>
</ul>
What happens if logged-out visitor makes a JSON/REST request? They will get only a simple message:
“rest_login_required: REST API restricted to authenticated users.”
This message may customized via the filter hook, <code>disable_wp_rest_api_error</code>. Check out <a href="https://wordpress.org/support/topic/not-entirely-for-non-techies/#post-12014965" rel="ugc">this post</a> for an example of how to do it.
Older versions of WordPress
For WordPress versions less than 4.7, this plugin simply disables all REST API functionality for all users.
More information available below in the FAQs section.
<h3>Privacy</h3>
This plugin does not collect or store any user data. It does not set any cookies, and it does not connect to any third-party locations. Thus, this plugin does not affect user privacy in any way. If anything it improves user privacy, as it protects potentially sensitive information from being displayed/accessed via REST API.
Disable WP REST API is developed and maintained by <a href="https://x.com/perishable" rel="nofollow ugc">Jeff Starr</a>, 15-year <a href="https://plugin-planet.com/" rel="nofollow ugc">WordPress developer</a> and <a href="https://books.perishablepress.com/" rel="nofollow ugc">book author</a>.
<h3>Support development of this plugin</h3>
I develop and maintain this free plugin with love for the WordPress community. To show support, you can <a href="https://monzillamedia.com/donate.html" rel="nofollow ugc">make a donation</a> or purchase one of my books:
<ul>
<li><a href="https://wp-tao.com/" rel="nofollow ugc">The Tao of WordPress</a></li>
<li><a href="https://digwp.com/" rel="nofollow ugc">Digging into WordPress</a></li>
<li><a href="https://htaccessbook.com/" rel="nofollow ugc">.htaccess made easy</a></li>
<li><a href="https://wp-tao.com/wordpress-themes-book/" rel="nofollow ugc">WordPress Themes In Depth</a></li>
<li><a href="https://books.perishablepress.com/downloads/wizards-collection-sql-recipes-wordpress/" rel="nofollow ugc">Wizard’s SQL Recipes for WordPress</a></li>
</ul>
And/or purchase one of my premium WordPress plugins:
<ul>
<li><a href="https://plugin-planet.com/bbq-pro/" rel="nofollow ugc">BBQ Pro</a> – Blazing fast WordPress firewall</li>
<li><a href="https://plugin-planet.com/blackhole-pro/" rel="nofollow ugc">Blackhole Pro</a> – Automatically block bad bots</li>
<li><a href="https://plugin-planet.com/banhammer-pro/" rel="nofollow ugc">Banhammer Pro</a> – Monitor traffic and ban the bad guys</li>
<li><a href="https://plugin-planet.com/ga-google-analytics-pro/" rel="nofollow ugc">GA Google Analytics Pro</a> – Connect WordPress to Google Analytics</li>
<li><a href="https://plugin-planet.com/head-meta-pro/" rel="nofollow ugc">Head Meta Pro</a> – Ultimate Meta Tags for WordPress</li>
<li><a href="https://plugin-planet.com/simple-ajax-chat-pro/" rel="nofollow ugc">Simple Ajax Chat Pro</a> – Unlimited chat rooms</li>
<li><a href="https://plugin-planet.com/usp-pro/" rel="nofollow ugc">USP Pro</a> – Unlimited front-end forms</li>
</ul>
Links, tweets and likes also appreciated. Thank you! 🙂

Disable WP REST API

while the plugin si deadsimple and very low resource impact, keep in mind that there are plugins that need the rest to work with no auth (ex. contact form 7).

dead simple and efficient, but be aware

Disables the WP REST API for visitors not logged into WordPress.

Dominate

<h3>About the app</h3>
Our cloud-based checkout suite includes everything you need to increase conversions and drop abandonment rates – yet it installs in just minutes and is completely free. If you ever decide you don’t want to use it anymore, uninstall it with just a single click.
With a single page for your entire checkout process, shoppers will have no problem becoming customers when they visit your WooCommerce website. Our checkout suite will give you all the tools to give them a completely frictionless checkout experience.
We understand your business is completely unique, which is why we made our checkout suite so it’s 100% customizable. Create the perfect checkout page for your specific website. Easily make adjustments over time to increase your conversion rate even further. No matter what kind of checkout page you build for your site, this extension’s completely responsive, so it will always display at the correct size.
Powered by PayPal Commerce, your customized checkout page will give you access to more than 280 million customers around the world and 100+ different currencies. You’ll also enjoy peace-of-mind knowing you’re benefiting from PayPal’s advanced Fraud Protection.
One simple page. One powerful extension. Start increasing conversions today.
<h3>App Features</h3>
Easy as 1-2-3 to Install and Customize 
Dominate Checkout solution is as powerful as it is easy to set up – no developer required! It only takes a few clicks to install and start converting more shoppers into customers. Effortlessly maintain your brand image across your entire conversion funnel with our user-friendly customization tools and give your consumers a seamless checkout experience.
Lightning Fast & Highly Scalable 
When it comes to your checkout page, speed is essential. Slow checkout pages mean high abandonment rates. We designed our checkout solution to be a cloud-based platform, so it’s lightning-fast and always available. WooCommerce’s checkout is focused on many aspects of your site, while Dominate Checkout Suite is solely focused on just your customer’s checkout journey – making it blazing fast and reliable!
Mobile Optimization Initiative 
IWD Agency partnered with Hi-Conversion, through the PayPal MOI initiative, to run countless A/B tests on mobile optimization. We then utilized the results when optimizing Checkout Suite for mobile users. Merchants that use our Checkout Suite see their conversion rates lift by 7.12% on average!

Disable WP REST API vs Dominate Checkout (SaaS)