How to disable/enable zlib.output_compression PHP directive in Plesk?

Benjamin Woellhardt

Updated May 08, 2026 09:13

kb: how-to Plesk for Linux php_value

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How to disable/enable zlib.output_compression PHP directive?

How to configure zlib.output_compression_level PHP directive?

How to enable/disable zlib.output_compression for PHP handler

Log into Plesk
Go to Tools & Settings > PHP Settings > <PHP version> > php.ini
Find and change the value of zlib.output_compression to a required one (on/off):

CONFIG_TEXT: zlib.output_compression = on
Scroll down and press the OK button to apply the changes

How to configure zlib.output_compression_level PHP directive?

Log into Plesk
Go to Tools & Settings > PHP Settings > <PHP version> > php.ini
To adjust the compression level, locate and modify the zlib.output_compression_level parameter.

CONFIG_TEXT: zlib.output_compression_level = -1

Note: Compression level used for transparent output compression. Specify a value between 0 (no compression) and 9 (maximum compression). The default value of -1 lets the server decide which level to use.
Scroll down and press the OK button to apply the changes