CI 4 Output Compression

In your Controller you can call for negotiator service to set gzip encoding.

PHP Code:

service('negotiator')->encoding(['gzip']); 


In your public/.htaccess you may define other resources by file-extension to be gzip encoded by apache.

Code:

<IfModule mod_deflate.c>
<FilesMatch "\.(js|css|html|htm|php|json|xml|jpg|jpeg|gif|raw)$">
SetOutputFilter DEFLATE
</FilesMatch>
</IfModule>

For apache gzip encoding to work: make sure you have this line uncommented in your apache/conf/httpd.conf

Code:

LoadModule deflate_module modules/mod_deflate.so

Let me know if it worked for you