How to Speed Up WordPress
Some things you can try to speed up wordpress would be the following. But backup wordpress before trying.
2. Deactive unused plugins.
3. You can use the Combine CSS and Combine JS plugins to combines, minifies, and compresses files. But don’t use if your caching plugin or other plugin is already combining and minifying your css and js files. Sometimes combining and minifying CSS/JS can break things. You have to test.
4. Use the Smush.it plugin to optimize your images as you upload them.
5. Optimize your database. You can do with phpMyAdmin or with some WordPress plugin like WP-Optimize or DB Manager
6. Not sure how much this would help (you can benchmark with Google Page Speed or Pingdom), but some say to slim your database by deleting post revisions (can do with plugin such as WP-Optimize) and delete spam comments. You can limit post revisions by adding …
define( ‘WP_POST_REVISIONS’, 3 );
to your wp-config.php file.
The following are for advance user who know how to manipulate code.
7. Re-work the code to put JS at the bottom of file if possible.
9. The WordPress theme that you are using can slow things down. Themes with a lot of options will require a lot of database access. Database access are expensive and time consuming. If you can eliminate these database calls by hard-coding the options into your template. I understand that this defeats the purpose of having options in the theme. But it is a tradeoff between convenience and performance.
10. Does your theme have foreign language support. And your site is only in one language that you don’t plan to internationalize. Then you can remove the foreign language support __(‘message’) and _e(‘message’)
11. Is your site using web fonts pulling fonts from another server. Or is it using embedded fonts for icons (that you are not using)? Consider using “web safe fonts” (remember those back in the days) that already exists in the user browser.
12. Is the theme a child theme? There might be a bit of inefficiency with child themes due to the use of @import and other redirections.