Gzip compression is a technique for minimizing file sizes, allowing quicker data transmission from the webserver to the browser. It is commonly applied to text files such as HTML, JavaScript, and CSS.
Gzip is a software that uses the Deflate algorithm as its primary compression method. Once the compression process is complete, the resulting files carry the .gz extension.
Gzip can achieve significant compression. Compared to other compression methods, Gzip can reduce file sizes by up to 70%. The value of a Gzip compression ratio depends on the compressed file type. Usually, text-based formats can be compressed more efficiently, unlike files that are already compressed, such as JPEG or PNG, or videos. The key advantage of Gzip lies in its speed, making it one of the fastest methods for compressing data efficiently.
Gzip compression aims to increase data transfer efficiency by reducing the amount of data that needs to be transmitted over a network. As a result, web loading speed improves, and bandwidth usage is significantly reduced.
Gzip uses the Deflate algorithm to reduce file sizes. Deflate is an effective compression algorithm that combines LZ77 compression and Huffman coding to minimize data size efficiently. The compression process involves several key steps:
Gzip scans data for duplicate sequences, such as words or characters that appear multiple times. The software replaces these sequences with shorter ones to make the file smaller while preserving all the original content.
After file compression, the server sends the file to the user’s browser. Because the file is smaller, it travels across the network much faster, reducing the amount of data and the transfer time.
After the transfer is complete and the compressed file reaches the user, the browser automatically decompresses it. It does that by detecting the Content-Encoding: gzip header and restoring the original form, making it ready for use.
If the browser does not support Gzip compression, the server sends an uncompressed version of the file instead to ensure all users can access the required content.
Gzip compression comes with multiple advantages that increase website performance and user experience.