*zlibCompressionLevel* - integer value from -1 - 9. This configuration option only applies to the zlib compressor. When zlib is not one of the compressors enumerated by the `compressors` configuration option then providing this option has no meaning.

-1 == Default Compression (usually 6)

 0 == No compression

 1 == Best Speed

 9 == Best Compression

Note that this value only applies to the client side compression level, not the response.