HTTP compression is used to reduce the amount (or size) of data transfers between a web server and a client. The server (or load balancer) compresses the content before sending it, and that data is decompressed upon receipt. While important for a wide range of applications, HTTP compression is especially important for web applications that handle many concurrent user requests—or in situations where first contentful paint markedly impacts user experiences.
How does HTTP compression work?
Algorithms like Gzip, Brotli, and others excel at compressing (encoding) data. They identify repetitive patterns or redundancies and replace them with shorter representations—resulting in a smaller overall packaging footprint. Transfer encoding headers for HTTP requests and content encoding headers can indicate if data packets are compressed while moving between a source and destination.
Why is HTTP compression useful?
The objective is to improve bandwidth utilization and transfer speeds, which can positively impact webpage load times, data retrieval times, and overall application performance.
File transfers get faster and page load times drop, to name a couple of examples. Text files can have as much as 60% redundancy—underscoring the need for optimization—and up to 70% size reductions are possible through compression.
Not convinced that compression is important? Here's some additional proof:
Compression is used on 88.7% of websites.
Gzip compression is used by 58.3% of websites with compression in place.
Website performance benchmarking tools like Google PageSpeed Insights, YSlow, and GTmetrix place great emphasis on compression when compiling speed scores.
Finally, most popular compression algorithms today are lossless, meaning they don't sacrifice any significant information throughout the compression process. This ensures better data integrity.
Does HAProxy offer HTTP compression?
Yes! HTTP compression is one of our most important application acceleration features within HAProxy. This aims to shrink server responses before they're delivered to the client. HAProxy supports gzip, deflate, identify (for debugging), and raw-deflate algorithms. Not only can you add a compression type (like text/css), but you can offload your compression onto HAProxy to reduce server strain under load.
