How to Configure Browser Caching for Nginx?

The first time you visit a domain, these files are downloaded and stored in the browser’s cache. On subsequent visits, the browser can serve the local versions instead of downloading the files again. This enables the web page to load much faster as it only needs to retrieve the data that has changed since the last visit. It offers a much better experience for users and is the reason Google’s PageSpeed Insights recommends that it be implemented.

You will add a small piece of code that will tell browsers to store CSS, JavaScript, images, and PDF files in their cache for a period of seven days or max.
Insert the following snippet inside the server block directly after the previous code for Gzip compression:

# vi /home/admin/conf/web/mail.datahead.biz.nginx.ssl.conf

location ~* ^.+\.(3gp|gif|bmp|jpg|jpeg|png|ico|wmv|avi|asf|asx|mpg|mpeg|mp4|pls|mp3|mid|wav|swf|flv|html|htm|txt|js|css|exe|zip|tar|rar|gz|tgz|bz2|uha|7z|doc|docx|xls|xlsx|pdf|iso|woff|ttf|svg|eot|sh)$ {
 expires max;
 add_header Pragma public;
 add_header Cache-Control "public";
 }

Another option that you may use

 location ~* ^.+\.(3gp|gif|bmp|jpg|jpeg|png|ico|wmv|avi|asf|asx|mpg|mpeg|mp4|pls|mp3|mid|wav|swf|flv|html|htm|txt|js|css|exe|zip|tar|rar|gz|tgz|bz2|uha|7z|doc|docx|xls|xlsx|pdf|iso|woff|ttf|svg|eot|sh)$ {
            expires     max;
            log_not_found off;
            add_header Pragma public;
            add_header Cache-Control "public, must-revalidate, proxy-revalidate";
 }