RestTemplate vs WebClient: Which Should You Use in Spring Boot?

If you’re building REST clients in Spring Boot, you’ve almost certainly asked this question:

Should I use RestTemplate or WebClient?

This guide gives you a clear, practical, production-ready answer — not just theory. By the end, you’ll know exactly when to use RestTemplate, when WebClient is the better choice, and how to migrate safely.

TL;DR

Use our cURL to Java Converter to generate both web and rest client.

Spring officially recommends WebClient for new development.

What Is RestTemplate?

RestTemplate is the traditional synchronous HTTP client provided by Spring. It has been widely used for years in Spring MVC applications.

Key Characteristics

• Blocking (thread-per-request)
• Simple, familiar API
• Built on HttpURLConnection / Apache HttpClient
• Designed for Spring MVC (Servlet stack)

Example: RestTemplate in Spring Boot

RestTemplaterestTemplate = newRestTemplate();

Stringresponse = restTemplate.getForObject(

“https://api.example.com/users/1”,

String.class

);

Pros

• Very easy to use
• Tons of legacy examples
• Works well for low-traffic apps

Cons

• Blocking I/O
• Poor scalability under high load
• Deprecated for new development

What Is WebClient?

WebClient is Spring’s modern, non-blocking HTTP client, introduced with Spring WebFlux.

Key Characteristics

• Non-blocking & reactive
• Built on Reactor + Netty
• Supports backpressure
• Works in both reactive and non-reactive apps

Example: WebClient in Spring Boot

WebClientwebClient = WebClient.create();

Mono<String> response = webClient.get()

.uri(“https://api.example.com/users/1”)

.retrieve()

.bodyToMono(String.class);

Blocking (if absolutely needed):

Stringresult = response.block();

⚠️ Blocking defeats WebClient’s biggest advantage — use carefully.

Blocking vs Non-Blocking (Core Difference

Architecture Diagram (Conceptual)

RestTemplate Flow (Blocking):
Client → Controller → Thread (WAITING) → External API → Response

WebClient Flow (Non-Blocking):
Client → Controller → Event Loop → External API (Async) → Callback → Response

This difference is why WebClient scales far better under load.

RestTemplate (Blocking)

• One request = one thread
• Thread waits until response arrives
• Limited scalability

WebClient (Non-Blocking)

• Event-loop based
• Threads are reused efficiently
• Handles thousands of concurrent calls with fewer resources

Visual Comparison

——|————|———–| | I/O model | Blocking | Non-blocking | | Thread usage | High | Low | | Scalability | Limited | Excellent | | Reactive support | ❌ | ✅ |

Is RestTemplate Deprecated?

Yes — but not removed.

• RestTemplate is in maintenance mode
• No new features will be added
• Spring recommends WebClient for all new code

RestTemplate is NOT removed in Spring Boot 3, but it is no longer the future.

Performance: WebClient vs RestTemplate

High-Level Comparison

Real-World Impact

• RestTemplate struggles under heavy traffic
• WebClient scales smoothly in microservices
• WebClient is ideal for API gateways and aggregators

Can You Use WebClient in Spring MVC (Non-Reactive)?

Yes. Absolutely.

WebClient works perfectly inside traditional Spring MVC apps.

Example (blocking usage):

Stringresponse = webClient.get()

.uri(“https://api.example.com/data”)

.retrieve()

.bodyToMono(String.class)

.block();

This allows gradual migration from RestTemplate.

Common WebClient Mistakes

1. Calling .block() Everywhere

• Eliminates non-blocking benefits
• Can cause thread starvation

2. Using WebClient Without Timeouts

• Leads to memory pressure

3. Mixing Reactive & Blocking Improperly

• Causes performance issues

When Should You Still Use RestTemplate?

You can continue using RestTemplate if:

• You maintain a legacy system
• Traffic is low
• Migration cost is high

But for new services, WebClient wins.

How to Migrate from RestTemplate to WebClient

🔗 Related Guides:

• WebClient Example in Spring Boot
• RestTemplate Deprecated: What to Use Instead
• WebClient Performance vs RestTemplate

Step-by-Step Strategy

Step-by-Step Strategy

1. Introduce WebClient as a bean
2. Replace RestTemplate calls incrementally
3. Start with non-critical APIs
4. Avoid .block() where possible

WebClient Bean Configuration

@Bean

publicWebClientwebClient(WebClient.Builderbuilder) {

returnbuilder

.baseUrl(“https://api.example.com”)

.build();

}

RestTemplate vs WebClient vs Feig

🔗 Related Comparison: WebClient vs Feign vs RestTemplate (Deep Dive)

| Feature | RestTemplate | WebClient | Feign |

Which One Should You Choose?

Choose WebClient if:

• You’re building new services
• You care about scalability
• You use Spring Boot 3+

Choose RestTemplate if:

• You’re maintaining old code
• Migration is risky short-term

Future-proof answer: WebClient ✅

FAQs

Is WebClient faster than RestTemplate?
Yes. WebClient is significantly faster and more resource-efficient under high concurrency because it uses non-blocking I/O.

Is WebClient only for reactive apps?
No. WebClient works perfectly in traditional Spring MVC applications as well.

Is RestTemplate deprecated in Spring Boot 3?
RestTemplate is not removed, but it is in maintenance mode and not recommended for new development.

Should I migrate from RestTemplate to WebClient?
Yes, especially for new features or high-traffic services.

Final Verdict

🔗 Next Reads (Highly Recommended):

• WebClient Example in Spring Boot (Production Ready)
• How to Migrate from RestTemplate to WebClient
• Is RestTemplate Deprecated? (Spring Official Direction)

RestTemplate vs WebClient is no longer a debate.

• RestTemplate = past
• WebClient = present & future

If you’re writing Spring Boot code in 2026 and beyond, WebClient is the correct choice.

Pro tip: Pair WebClient with proper timeouts, retries, and observability for production-grade systems and use our generator to generate java code.