PHP gzcompress() Function: Usage and Examples

Use gzcompress() when you need to compresses a string using the zlib data format in a PHP application. The examples below show the actual operation and its limitations.

What Is gzcompress() in PHP?

Compresses a string using the zlib data format. The exact signature supported by your installation depends on its PHP version and enabled extensions.

Its syntax is:

gzcompress(string $data, int $level = ..., int $encoding = ...): string|false

Parameters and return value: The parameter types, optional arguments, references, and return type are shown in the signature above. Optional parameters are marked with an ellipsis in this reference signature.

Example 1: Basic Usage

<?php

$compressed = gzcompress("Hello Hello"); echo gzuncompress($compressed);

Output:

Hello Hello

Example 2: Different Input or Behavior

<?php

$compressed = gzcompress(str_repeat("A",100)); echo strlen($compressed) < 100 ? "Smaller" : "Not smaller";

Output:

Smaller

Practical Example: Applying the Function

<?php

$message = "Saved configuration"; $packed = gzcompress($message, 6); echo gzuncompress($packed);

Output:

Saved configuration

Important Behavior and Edge Cases

A compressed value is binary data, not encrypted and not necessarily smaller than the original.

Comparison With Related Functions

Common Beginner Mistakes

Key Takeaways

• Compresses a string using the zlib data format.
• A compressed value is binary data, not encrypted and not necessarily smaller than the original.
• gzdeflate() creates raw DEFLATE data instead of zlib-wrapped data.

Use gzcompress() for the specific operation demonstrated above. Check its prerequisites and handle failure conditions before using it with production data.