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<gzclosegzdecode>
^Zlib FunctionsLast updated: Mon, 26 Oct 2026

gzcompress

(PHP 4 >= 4.0.1, PHP 5, PHP 7, PHP 8)

gzcompress — Compress a string

Description

function gzcompress(string $data, int $level = -1, int $encoding = ZLIB_ENCODING_DEFLATE): string|false

This function compresses the given string using the ZLIB data format.

For details on the ZLIB compression algorithm see the document "» ZLIB Compressed Data Format Specification version 3.3" (RFC 1950).

Note:

This is not the same as gzip compression, which includes some header data. See gzencode() for gzip compression.

Parameters

data

The data to compress.

level

The level of compression. Can be given as 0 for no compression up to 9 for maximum compression.

If -1 is used, the default compression of the zlib library is used which is 6.

encoding

One of ZLIB_ENCODING_* constants.

Return Values

The compressed string or false if an error occurred.

Examples

Example #1 gzcompress() example

<?php
$compressed = gzcompress('Compress me', 9);
echo $compressed;
?>

See Also


<gzclosegzdecode>
^Zlib FunctionsLast updated: Mon, 26 Oct 2026