WordPress REST API: What It Is and How to Get Started Using It

WordPress REST API

The term REST API refers to the Representational State Transfer API. It points to the kind of architecture of applications that rules the manner web services can work and have mutual communication by using HTTP. The protocol launched way back in 2013 attracted the contribution of the developers worldwide and was introduced to the WordPress core in the year 2015. Now WordPress REST API is looked after as a crucial tool for extending the functional capabilities of the WordPress platform.

As the situation stands, the vast majority of professional WordPress developers have heard about and used the REST API. Though it is also true that only a handful of WordPress developers as of now could actually realize the extensive potential of this protocol for delivering better user experience. The protocol offers really huge scope for strengthening the features and capabilities of the WordPress websites. 

Developers can create API keys to access REST API here.

WordPress REST API basically works like the integrated solution to extend the capabilities of mobile apps, themes, plugins, and many others. Thanks to this REST API, WordPress websites can easily interact with other apps. By using the REST API developers can also develop custom APIs as needed by them.

How REST API Extends The Capabilities of WordPress Websites? 

Let us provide here some examples of the usage of REST API in real-life WordPress development scenarios.  

  • WordPress REST API can be utilized to allow developers access to the deep-lying infrastructure. Because of this access developers can build apps as per the available services.
  • A WordPress plugin thanks to the REST API helps developers to build custom apps using the same API used by the developers of the plugin. For example, ACF to REST API plugin helps to expose Advanced Custom Fields endpoints in the WordPress REST API.

WordPress REST API

Application Programming Interfaces (API) are of many types and they are frequently used for building custom apps, plugins, extensions, and themes that can be utilized in different contexts. REST API among all these different types of APIs offers a distinct standard. These APIs don’t need to access the UI or the database of an app but it can make use of data across contexts. 

REST API uses the HyperText Transfer Protocol (HTTP) language for communication and JavaScript Object Notation (JSON) code for the purpose of formatting. For  WordPress pages, posts, and different types of data HTML language is used while formatting JSON is used. For a better understanding of how WordPress API works, learning the JSON formatting is necessary. 

Why Is The WordPress REST API Important For WordPress Developers?

Just because JSON formatting is used by the WordPress REST API, WordPress websites can easily send and receive data to and from other applications and websites. This also offers great flexibility and freedom to the developers who don’t need to stick to PHP and instead they can utilize REST API for the same purpose.

Thanks to the dominant presence of REST API, PHP is no longer the must-learn language for working on WordPress websites. REST API being developed using JavaScript reduces the importance of PHP for WordPress development. Already we have the key software running behind WordPress.com such as Calypso which is built completely using REST API as well as JavaScript. 

How Can Developers use WordPress REST API?

When your WordPress website is fully ready, there are a lot of scopes to utilize the REST API capabilities for improving the web experience. The developers can send different GET requests for the purpose of getting access to the data right from the browsers. 

For using the WordPress REST API here we are going to provide the clear steps. 

  • Consult the REST API Handbook which is regarded to be the official WordPress resource comprising every detailed data regarding the REST API. This documentation will also allow you to see all the endpoints to be presented by the REST APIs.  
  • You can also learn a lot from the W3Schools tutorials. Though this tutorial is not just about REST API, it is handy to have basic training on the elementary aspects and elements like HTTP coding and JSON formatting.
  • There is a free resource from WP Engine and it is named as Ultimate Guide to the WordPress REST API. The developers can easily access a lot of information free of cost. Most importantly, such practical help and information come with relevant examples. The guidebook helps developers to carry out several tasks by using the REST API. 
  • Apart from all these guiding resources and tutorials, developers will find practical examples of several successful WordPress plugins development helpful. Consider learning about these plugins that used REST API to accomplish their features.

In spite of all these resources, examples, and guidebooks, we must admit that WordPress REST API is really a complicated and multi-layered subject. But even WordPress website owners without any developer background should have a basic understanding of the REST API for improving their own websites or just to have a proper improvement plan. 


Let us admit that for an aspiring developer it is the ideal time to learn REST API since across WordPress websites offering custom user experience has become a consistent focus area. After the WordPress REST API has been completely integrated into the WordPress core, this is likely to have a better say in the future of the platform. For any WordPress developer now for extending the functionalities and user experience, REST API offers a great package of value additions. Many things that were earlier challenging for the developers can now be implemented thanks to this API. 

Now, for beginners to understand the intricacies and underlying concepts of the REST API can be a little problematic. The basic concept is to use a ready protocol that facilitates communication among different web services. The API basically allows manipulation of the data for extending functionalities of a WordPress website.  As a WordPress developer you can hardly do without a sound knowledge of this protocol and the way it works. Here we have put a small effort to enrich developers’ knowledge about WordPress REST API.

Further reading