As headless WordPress architecture gains traction, a common question arises: Should you opt for the WordPress REST API or GraphQL (via WPGraphQL) for your headless build?
For developers creating modern front-end experiences with frameworks like React, Next.js, Nuxt, or Svelte, the choice of API can significantly impact performance, scalability, and the developer experience.
This guide will explore the differences between WordPress REST API and GraphQL, compare them, and help you decide the best option for your headless WordPress project.
What Is Headless WordPress, and Why the API Matters
Headless WordPress involves using WordPress solely as a backend CMS, without relying on PHP themes. Instead, a front-end framework (e.g., Next.js, React, Gatsby, Astro) consumes content via an API.
The API is the lifeline of your application.
– Every post, page, menu, ACF field, or CPT eventually runs through it.
– Your API impacts speed, caching, payload size, security, and server load.
– Depending on your tech stack, one API may offer a smoother developer workflow.
Choosing between REST API or GraphQL in WordPress isn’t just a technical detail—it determines how flexible your content model feels and how fast your front end runs.
Understanding the WordPress REST API
How the REST API Works
The WordPress REST API is built into WordPress core. It exposes your content using simple, predictable JSON endpoints like:
/wp-json/wp/v2/posts /wp-json/wp/v2/pages /wp-json/wp/v2/categories
Developers can fetch data with a standard GET request and get a full JSON object in return.
Strengths of the REST API
– Native to WordPress: No plugins needed, no configuration—REST works instantly on every WordPress install.
– Simple, predictable endpoints: Perfect for beginners or lightweight front-ends.
– Easy caching: CDNs like Cloudflare, Fastly, and Akamai cache REST responses efficiently.
– Works great with SSG and ISR: Since the responses are static JSON, frameworks like Next.js or Astro can quickly pre-render pages.
Limitations of the REST API
REST’s simplicity is also its biggest weakness:
– Over-fetching and under-fetching: You often get more data than you need—or not enough. For example, if you need a post and its related author fields and related categories, you may need three separate REST requests.
– Multiple round-trips: Complex queries = multiple API calls.
– Limited flexibility: While you can add custom endpoints, it requires extra programming and maintenance.
For simple sites, REST works great. But for large headless ecosystems, this rigidity can slow development.
Understanding GraphQL in WordPress (via WPGraphQL)
What Is GraphQL?
GraphQL is a query language created by Facebook. Instead of multiple endpoints, GraphQL uses one single endpoint and allows the client to request exactly the fields it wants.
No more over-fetching. No more under-fetching.
Using GraphQL in WordPress
GraphQL is not built into WordPress core, but the WPGraphQL plugin adds a full GraphQL schema and query interface.
Developers can query deeply related content in a single request:
query { post(id: “hello-world”, idType: SLUG) { title date author { name } categories { nodes { name } } } }
This eliminates several REST calls.
Strengths of GraphQL for Headless Builds
– Fetch exactly what you need: No extra payload. No wasted API calls.
– One endpoint for everything: Ideal for React, Next.js, and modern front-end frameworks.
– Strongly typed schema: GraphiQL explorer lets developers visually browse fields and auto-generate queries.
– Nested relationships: GraphQL excels at relational content models with CPTs, ACF fields, and content relationships.
Limitations of GraphQL in WordPress
– Requires plugins: WPGraphQL must remain installed and maintained.
– More complex caching: Because GraphQL queries vary, edge caching is trickier (though persisted queries help).
– Potential performance overhead: Poorly optimized GraphQL resolvers may hit performance limits on very large sites.
GraphQL is powerful, but it demands thoughtful setup.
REST API vs GraphQL WordPress: Side-by-Side Comparison
Below is a practical comparison for developers deciding between the two.
Performance
REST API:
– Very easy to cache
– Lightweight, stable, and predictable
– Ideal for high-traffic static and semi-static sites
GraphQL:
– Fewer total requests
– More efficient querying
– Needs caching strategies like persisted queries for best performance
Verdict: For raw speed and CDN caching: REST wins. For optimized query efficiency: GraphQL wins.
Flexibility & Query Control
REST:
– One endpoint per resource
– Harder to fetch relational data
– Requires custom endpoints for complex queries
GraphQL:
– One endpoint for everything
– Perfect
