GZip in Rest APi
1. What is Gzip in REST API?
- Gzip is a popular lossless compression algorithm.
- In the context of REST APIs, Gzip can compress the HTTP request body (client → server) or the response body (server → client).
- Compression reduces payload size, which makes data transfer faster over the network.
It works with the Content-Encoding header:
- Request from client:
Accept-Encoding: gzip
(client says “I can accept compressed responses”)
- Server response:
Content-Encoding: gzip
(server says “Here’s the response, compressed with gzip”)
2. When to Use Gzip
Good use cases:
- Large JSON/XML responses (e.g., reports, analytics data, big lists).
- APIs with high traffic over slow/limited networks (mobile, IoT).
- Reducing bandwidth costs on public APIs.
- Serving static content (HTML, CSS, JS, JSON, XML).
Avoid Gzip:
- Very small responses (e.g.,
{"status":"ok"}), since compression overhead may make it larger. - Already compressed data (images:
.jpg,.png,.gif,.zip,.mp4). Gzip won’t help here. - Low-latency APIs (where CPU overhead of compressing/decompressing might be worse than bandwidth savings).
- Internal microservice calls in high-performance clusters (if network speed >> CPU cost).
3. Benefits
- Performance: Faster API responses over the internet.
- Reduced bandwidth usage: Can cut JSON payloads by 60–80%.
- Better client experience: Especially important for mobile users.
Tradeoff:
CPU usage ↑ (to compress/decompress) vs Network bandwidth ↓.
4. How to Enable Gzip in Spring Boot
Spring Boot provides built-in support (since 1.3+) through properties.
Option 1: Configure in application.properties
# Enable response compression
server.compression.enabled=true
# Minimum response size before compression is applied
server.compression.min-response-size=1024
# MIME types that should be compressed
server.compression.mime-types=application/json,application/xml,text/html,text/plain,text/css,text/javascript,application/javascript
Option 2: Configure in application.yml
server:
compression:
enabled: true
mime-types: application/json,application/xml,text/html,text/plain,text/css,text/javascript,application/javascript
min-response-size: 1KB
5. Example Flow
Client request:
GET /api/users HTTP/1.1
Host: example.com
Accept-Encoding: gzip
Server response (compressed):
HTTP/1.1 200 OK
Content-Encoding: gzip
Content-Type: application/json
[binary gzipped data here]
6. Testing
You can test using cURL:
curl -H "Accept-Encoding: gzip" -I http://localhost:8080/api/users
You should see:
Content-Encoding: gzip
Or in Postman, set Accept-Encoding: gzip.
Summary
- Use Gzip for large payloads or high-traffic APIs.
- Avoid for tiny or already-compressed responses.
- In Spring Boot, just enable via
application.propertiesorapplication.yml.
