Here is four simple tips that can be used to optimize WordPress performance.
1. Keep WordPress Up to Date
Keeping WordPress and the plugins within it is probably the most important rule of all if you want to optimize WordPress performance. Not only does this assist in your sites performance, but it will increase the security of your site.
WordPress keeps itself up to date for minor revisions and security updates, but major revisions still require manual intervention. Install a plugin like the WP Updates Notifier to alert you to updates that may be available for both the WordPress core, and your plugins.
2. Remove unnecessary plugins
Ask yourself how much you really need that Hello Dolly plugin. Or that one-time-use transfer website plugin you used to move your site to your new host. Having these plugins installed can reduce the performance of your site. Enable only what you need, and delete the rest.
3. Replace slow plugins
Some plugins are simply better written than others. Using a profiler plugin such as the P3 (Plugin Performance Profiler) can give you a better insight into which plugins are slowing your site down. When you’ve identified a slow plugin, you can either troubleshoot its configuration, or look for a different plugin that does the same job, better.
4. Use a caching plugin
Sometimes it can take a while to render complicated website designs from scratch. But generally, pages don’t need to be rendered from scratch on every single page load. Enter caching.
There is several different types of cache plugins out there, from the extreme plugins that generate raw HTML files to be served up to the end user without involving WordPress, to those that involve complicated CDN networks to distribute the load over many services.
Check out W3 Total Cache, and WP Super Cache.