WordPress, by default, comes uncompressed and sends the uncompressed HTML to the visitor’s browser. With one line of code added to your header, you can compress WordPress’s output by up to 75%. By using zlib compression technology, you can harness the power of PHP and reduce your blog’s load speed!
<?php phpinfo(); ?>
Make sure that “zlib” is enabled by your hosting provider.
Second, place the following code in your header (above the DOCTYPE):
<?php ini_set('zlib.output_compression', 'On'); ini_set('zlib.output_compression_level', '1'); ?>