REST Resource Representation Compression

Compression in REST APIs helps reduce payload size, improve response times, and save bandwidth when transferring large amounts of data over the network. By using Gzip or Brotli compression, REST APIs can significantly improve performance, especially in high-traffic applications.

In this article, we’ll cover:

✔ What is REST API Compression?
✔ Why Use Compression in REST APIs?
✔ Common Compression Algorithms (Gzip, Brotli, Deflate)
✔ How to Enable Compression in Spring Boot REST APIs?
✔ Best Practices for API Compression

Let’s get started! 🚀

🔹 What is REST API Compression?

REST resource representation compression is the process of reducing the size of JSON, XML, or other responses before sending them to the client.

📌 Without Compression:

Content-Length: 5000 bytes

📌 With Compression (Gzip):

Content-Length: 1200 bytes  ✅ (Smaller payload = Faster response)
Content-Encoding: gzip

By compressing API responses, we reduce data transfer time and enhance API performance.

🔹 Why Use Compression in REST APIs?

✅ Faster API responses – Smaller payloads mean quicker data transfers.
✅ Lower bandwidth usage – Saves network traffic, especially for mobile and slow connections.
✅ Improved scalability – APIs can handle more users with less resource consumption.
✅ Better user experience – Reduces page load time and improves app performance.

💡 When Should You Use Compression?
✔ Large JSON/XML responses (e.g., product catalogs, reports).
✔ Slow network connections (e.g., mobile users).
✔ High-traffic applications (e.g., social media, e-commerce).

🔹 Common REST API Compression Algorithms

Compression Algorithm	Description	Best Used For
Gzip	Fast and widely supported	JSON, HTML, text responses
Brotli	Better compression than Gzip, slower	Web pages, large JSON data
Deflate	Faster but less efficient than Gzip	Real-time compression

📌 Gzip is the most widely used compression format for REST APIs due to its balance of speed and compression ratio.

🔹 How to Enable Compression in Spring Boot REST APIs?

Spring Boot provides built-in support for response compression using Gzip.

1️⃣ Enable Gzip Compression in application.properties

📌 Just add these lines to enable compression:

server.compression.enabled=true
server.compression.mime-types=application/json,application/xml,text/html,text/plain
server.compression.min-response-size=1024

✅ What This Does?
✔ Enables Gzip compression for API responses.
✔ Compresses JSON, XML, HTML, and text responses.
✔ Compresses responses larger than 1 KB.

2️⃣ Verify Compression in REST API Response

📌 Send a request to the REST API:

GET /products HTTP/1.1
Accept-Encoding: gzip
Host: api.example.com

📌 Compressed Response:

HTTP/1.1 200 OK
Content-Encoding: gzip
Content-Length: 1500

✅ The API automatically compresses the response when the client supports it (Accept-Encoding: gzip).

3️⃣ Enable Brotli Compression for Better Performance

Brotli offers better compression than Gzip, but it is not enabled by default in Spring Boot.

📌 Step 1: Add Brotli Support using mod_brotli (For Nginx/Apache)

sudo a2enmod brotli  # Enable Brotli in Apache

📌 Step 2: Update application.properties to Use Brotli

server.compression.enabled=true
server.compression.mime-types=application/json,application/xml,text/html,text/plain
server.compression.min-response-size=1024
server.compression.brotli.enabled=true

📌 Step 3: Verify Brotli Compression in API Response

GET /products HTTP/1.1
Accept-Encoding: br

📌 Brotli Compressed Response:

HTTP/1.1 200 OK
Content-Encoding: br
Content-Length: 1200

🚀 Brotli compression further reduces response size, improving API speed.

🔹 Implementing Custom Compression Filter in Spring Boot

For custom compression logic, you can use a Spring Boot filter.

📌 Create a Gzip Compression Filter in Java

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.zip.GZIPOutputStream;

@WebFilter("/*")  // Apply to all API endpoints
public class GzipCompressionFilter implements Filter {

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        HttpServletResponse httpServletResponse = (HttpServletResponse) response;
        httpServletResponse.setHeader("Content-Encoding", "gzip");

        GZIPOutputStream gzipOutputStream = new GZIPOutputStream(response.getOutputStream());
        chain.doFilter(request, new GzipResponseWrapper(httpServletResponse, gzipOutputStream));
        gzipOutputStream.close();
    }
}

🚀 This applies Gzip compression to all API responses, improving efficiency.

🔹 Best Practices for REST API Compression

✅ Use Gzip or Brotli for large JSON/XML responses
✅ Enable compression in Spring Boot using server.compression.enabled=true
✅ Use HTTP headers (Accept-Encoding: gzip, br) to detect client support
✅ Set a minimum response size (server.compression.min-response-size=1024) to avoid compressing small payloads
✅ Test API performance with and without compression to ensure optimal results

🔹 Summary: Why Use Compression in REST APIs?

Benefit	Why It Matters?
🚀 Faster API Responses	Smaller payloads reduce network latency
⚡ Lower Bandwidth Usage	Reduces data transfer costs
🌍 Improved Scalability	Handles more users with less resource consumption
🔄 Better User Experience	Faster page loads and API responses
✅ Works with Modern Browsers & Clients	Supports Gzip and Brotli compression

🚀 Final Thoughts

Compression is one of the easiest ways to improve REST API performance. By enabling Gzip/Brotli in Spring Boot, developers can reduce response size, speed up APIs, and enhance user experience.

💡 Want to optimize your REST API? Enable compression today and make your APIs faster and more efficient! 🚀