If you don’t want to use cache plugins for whatever reasons you have, there are still things you can do to optimize your website.

Enabling Gzip Compression

Gzip compresses your files such as CSS and HTML. Most of the time, Gzip compresses your file size more than 50%. Use this Gzip check tool to know how much Gzip saves for your webpage.

Activate Gzip to optimize your file delivery. Activating Gzip depends on server and its configuration. For Apache you can try below codes. Paste the codes in .htaccess file.

Note: .htaccess is an important file for your website, be careful when working with it. We recommend you to create a backup of your website first.

  # Compress HTML, CSS, JavaScript, Text, XML and fonts
  AddOutputFilterByType DEFLATE application/javascript
  AddOutputFilterByType DEFLATE application/rss+xml
  AddOutputFilterByType DEFLATE application/vnd.ms-fontobject
  AddOutputFilterByType DEFLATE application/x-font
  AddOutputFilterByType DEFLATE application/x-font-opentype
  AddOutputFilterByType DEFLATE application/x-font-otf
  AddOutputFilterByType DEFLATE application/x-font-truetype
  AddOutputFilterByType DEFLATE application/x-font-ttf
  AddOutputFilterByType DEFLATE application/x-javascript
  AddOutputFilterByType DEFLATE application/xhtml+xml
  AddOutputFilterByType DEFLATE application/xml
  AddOutputFilterByType DEFLATE font/opentype
  AddOutputFilterByType DEFLATE font/otf
  AddOutputFilterByType DEFLATE font/ttf
  AddOutputFilterByType DEFLATE image/svg+xml
  AddOutputFilterByType DEFLATE image/x-icon
  AddOutputFilterByType DEFLATE text/css
  AddOutputFilterByType DEFLATE text/html
  AddOutputFilterByType DEFLATE text/javascript
  AddOutputFilterByType DEFLATE text/plain
  AddOutputFilterByType DEFLATE text/xml

  # Remove browser bugs (only needed for really old browsers)
  BrowserMatch ^Mozilla/4 gzip-only-text/html
  BrowserMatch ^Mozilla/4\.0[678] no-gzip
  BrowserMatch \bMSIE !no-gzip !gzip-only-text/html
  Header append Vary User-Agent

Also below code should works for Apache too:

mod_gzip_on Yes
mod_gzip_dechunk Yes
mod_gzip_item_include file .(html?|txt|css|js|php|pl)$
mod_gzip_item_include handler ^cgi-script$
mod_gzip_item_include mime ^text/.*
mod_gzip_item_include mime ^application/x-javascript.*
mod_gzip_item_exclude mime ^image/.*
mod_gzip_item_exclude rspheader ^Content-Encoding:.*gzip.*

Leverage Browser Cache

We talked about browser cache before. Leverage browser cache by plugins is an easy task. Doing it manually should be easy task too but might be different from one server to another. Try below codes in .htaccess file.

Note: .htaccess is an important file for your website, be careful when working with it. We recommend you to create a backup of your website first.

<filesMatch ".(css|jpg|jpeg|png|gif|js|ico)$">
Header set Cache-Control "max-age=2592000, public"
</filesMatch>

Also below codes should work:

ExpiresActive On
ExpiresByType image/jpg "access plus 1 month"
ExpiresByType image/jpeg "access plus 1 month"
ExpiresByType image/gif "access plus 1 month"
ExpiresByType image/png "access plus 1 month"
ExpiresByType text/css "access plus 1 year"
ExpiresByType application/pdf "access plus 1 month"
ExpiresByType text/x-javascript "access plus 1 month"
ExpiresByType application/x-shockwave-flash "access plus 1 month"
ExpiresByType image/x-icon "access plus 1 month"
ExpiresDefault "access plus 2 days"

You can change expiry time for every type you want in above codes.

Optimize as WordPress Says!

WordPress official website has guides for this topic i.e WordPress Optimization. Of course reading it is beneficial for you.

What Else?

There are other things you can do to optimize your website. We will talk about them in upcoming sections. Keep reading Performance Optimization.