Spring WebClient vs. RestTemplate: Which One Should You Use in 2025?

Source: Dev.to

If you’ve been in the Spring ecosystem for more than a few years, RestTemplate is like an old friend. It’s familiar, it’s synchronous, and—let’s be honest—it just works. But if you are starting a new Spring Boot 3.x project in 2025, reaching for that old friend might be the first technical debt you introduce to your codebase.

The debate of Spring WebClient vs RestTemplate isn’t just about syntax preference anymore; it’s about architectural longevity. With the release of Spring Framework 6 and Spring Boot 3, the landscape has shifted significantly. We now have three contenders: the legacy RestTemplate, the reactive powerhouse WebClient, and the new kid on the block, RestClient.

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The Legacy: Is RestTemplate Dead?

Technically, no. The @Deprecated annotation hasn’t been slapped on it yet. However, the Spring documentation has been explicit for years: RestTemplate is in maintenance mode. This means no new features—only minor bug fixes.

Why? Because it is blocking.

RestTemplate follows the “one thread per request” model. When your application makes an external API call, the thread handling that request sits there, doing nothing, waiting for the response. In 2015 this was fine; in 2025, where cloud‑native microservices run on expensive compute resources, blocking threads burn money.

When to still use it

• You are maintaining a legacy application that hasn’t upgraded to Spring Boot 3.
• The integration is simple, and the overhead of reactive programming isn’t justified.

When you compare Spring WebClient vs RestTemplate, the performance difference under load is staggering. WebClient uses an event‑loop model (similar to Node.js). A small number of threads can handle thousands of concurrent requests because they don’t block. They fire the request and move on, processing the response only when it comes back.

Here is what a standard GET request looks like in WebClient:

WebClient client = WebClient.create("https://api.example.com");

// Asynchronous / Non‑blocking
// Nothing happens until you subscribe!
client.get()
      .retrieve()
      .bodyToMono(String.class)
      .subscribe(System.out::println);

If you need high throughput—like an API gateway or a service that aggregates data from multiple upstream services—WebClient is non‑negotiable.

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The New Standard: Spring 6 RestClient

Enter RestClient. Introduced in Spring Boot 3.2, RestClient is the official replacement for RestTemplate. It offers the same fluent API style as WebClient but runs on the Servlet stack (blocking I/O) by default.

Why is this a big deal? It means you can write modern, readable code without adopting a fully reactive stack:

RestClient client = RestClient.create("https://api.example.com");

User user = client.get()
                 .uri("/users/{id}", 42)
                 .retrieve()
                 .body(User.class);

Default Choice: Use Spring RestClient. It is the modern standard for the majority of microservices—easy to read, easy to test, and removes the verbosity of RestTemplate while keeping the simplicity of synchronous code.

If you find yourself Googling “how to set bearer token in spring restclient” repeatedly, consider using a cURL‑to‑Java converter. Paste your raw cURL command, and it generates the exact Java code for WebClient, RestClient, or even OkHttp, handling JSON escaping and header mapping for you.

👉 Try the cURL to Java Converter here

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Final Thoughts

Stop writing new HttpEntity<> wrappers. Upgrade your client stack, and your future self (debugging production at 3 AM) will thank you.