You can improve your Joomla or WordPress website speed a lot by making the few changes below:
Before making any changes, check your current home page report using Google pagespeed insights: https://developers.google.com/speed/pagespeed/insights/
1- (WordPress users skip to #2) Go to the Joomla global configuration and enabled "GZip compression" under "Server".
2- open your website .htaccess file (it's usually under the web site root directory when you FTP to your website or when you open the files manager in your hosting cPanel) and append the following lines:
<IfModule mod_deflate.c> AddOutputFilterByType DEFLATE text/plain AddOutputFilterByType DEFLATE text/html AddOutputFilterByType DEFLATE text/xml AddOutputFilterByType DEFLATE text/css AddOutputFilterByType DEFLATE application/xml AddOutputFilterByType DEFLATE application/xhtml+xml AddOutputFilterByType DEFLATE application/rss+xml AddOutputFilterByType DEFLATE application/javascript AddOutputFilterByType DEFLATE application/x-javascript AddOutputFilterByType DEFLATE image/x-icon image/svg+xml AddOutputFilterByType DEFLATE application/vnd.ms-fontobject AddOutputFilterByType DEFLATE application/x-font-ttf AddOutputFilterByType DEFLATE font/opentype </IfModule>
2- Append the mod_expires code to the same .htaccess file:
<IfModule mod_expires.c> ExpiresActive On ExpiresByType image/jpg "access plus 1 week" ExpiresByType image/jpeg "access plus 1 week" ExpiresByType image/gif "access plus 1 week" ExpiresByType image/png "access plus 1 week" ExpiresByType text/css "access plus 1 week" ExpiresByType application/pdf "access plus 1 week" ExpiresByType text/x-javascript "access plus 1 week" ExpiresByType application/x-shockwave-flash "access plus 1 week" ExpiresByType image/x-icon "access plus 1 week" ExpiresDefault "access plus 1 week" </IfModule>
The changes above should have a big impact on your web page speed, you can now check your website again using the Google pagespeed insights.