Spring Boot vs Quarkus: Performance Comparison, Native Image Benefits, and Migration Guide

Spring Boot

Spring Boot is a Java‑based framework focused on enterprise applications, offering convention‑over‑configuration, auto‑registration of defaults, and many out‑of‑the‑box features that speed up development.

Quarkus

Quarkus is a Kubernetes‑native Java framework built for OpenJDK HotSpot and GraalVM, promising supersonic startup, subatomic memory usage, and optimized native image generation for cloud, serverless, and container environments.

Comparison

Both frameworks integrate well with other libraries, but their internal architectures differ: Spring Boot provides blocking (Servlet) and non‑blocking (WebFlux) web stacks, while Quarkus supports both simultaneously and embeds a reactive programming model.

Test Application

The benchmark implements three APIs (create, lookup by postal code, and city‑based query) using reactive approaches of Spring WebFlux and Quarkus, with PostgreSQL as the database.

Test Plan

JMeter runs a 5‑minute load test, gradually increasing concurrent users up to 1,500, while VisualVM monitors CPU and memory. Tests are executed on a specified hardware configuration.

Results

Quarkus shows roughly double the startup speed of Spring Boot in both JVM and native modes, builds faster (20 s vs 39 s for JVM, 9 min vs 13 min for native), and produces smaller artifacts (75 MB vs 109 MB native, 4 KB vs 26 MB JVM).

CPU

During warm‑up, JVM versions consume more CPU, after which usage stabilizes; Quarkus native and JVM versions exhibit similar CPU patterns.

Memory

Both JVM versions reserve significant heap, yet Quarkus consistently uses less memory overall, with lower peak usage even though native runs show higher spikes.

Response Time

Spring Boot JVM slightly outperforms Quarkus in response time and thread usage, benefiting from JIT optimizations, while Quarkus native shows strong low‑resource performance.

Migration from Spring to Quarkus

Quarkus offers Spring API compatibility (DI, Web, Data JPA) and leverages the same Java libraries without reflection for native compilation. Developers can transition by using the provided code examples and following the recommended learning steps.

Code Example – Quarkus Spring Web Controller

import java.util.List;
import java.util.Optional;
import org.springframework.web.bind.annotation.*;

@RestController
@RequestMapping("/person")
public class PersonController {
    @GetMapping(path = "/greet/{id}", produces = "text/plain")
    public String greetPerson(@PathVariable(name = "id") long id) {
        String name = "";
        // ...
        return name;
    }

    @GetMapping(produces = "application/json")
    public Iterable
findAll() {
        return personRepository.findAll();
    }
}

Code Example – Quarkus Spring Repository

package org.acme.springmp;

import java.util.List;
import org.springframework.data.repository.CrudRepository;

public interface PersonRepository extends CrudRepository
{
    List
findByAge(int age);
}

Code Example – Quarkus Spring Service with MicroProfile Fault Tolerance

import org.eclipse.microprofile.faulttolerance.Fallback;
import org.eclipse.microprofile.faulttolerance.Timeout;
import org.eclipse.microprofile.rest.client.inject.RestClient;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;

@Service
public class PersonService {
    @Autowired
    @RestClient
    SalutationMicroProfileRestClient salutationRestClient;

    @Value("${fallbackSalutation}")
    String fallbackSalutation;

    @CircuitBreaker(delay=5000, failureRatio=.5)
    @Fallback(fallbackMethod = "salutationFallback")
    public String getSalutation() {
        return salutationRestClient.getSalutation();
    }
}

Additional Benefits for Spring Developers

Fast startup for FaaS (≈0.0015 s native)

Live coding without restarts

Support for both reactive and imperative models

Compile‑time detection of CDI errors

Combination of best‑of‑breed frameworks and standards

Getting Started

Follow the Quarkus getting‑started guide, explore Spring DI, Spring Web, and Spring Data JPA extensions, and use code.quarkus.io to generate a new project.