WordPress Performance - Introduction

WordPress Performance, WordPress site tuning, WordPress site performance optimization, etc., refers to the various practices, techniques, and tools used to optimize the speed and efficiency of a WordPress website. A well-performing WordPress site not only provides a better user experience but also ranks higher in search engine results. In the articles on this wiki, this topic mostly relates to the performance of WooCommerce webshops, where both factors should translate into increased sales. Also: caching is only one aspect of 'site performance.

Some aspects

Some aspects of WordPress performance, roughly in order from measurement » server » client:

1. Develop performance policy: Explicitly state goals, measurement approaches and resources. E.g.: To what price is performance improvement important?
2. Procedures for continuous measurement & optimization. E.g.: Regular site & plugin updates, server updates, reviews & discussions, dashboarding
3. External performance measuring: External tools like Google PageSpeed, GTmetrix and Pingdom
4. Internal performance measuring: Tools like plugin Query Monitor
5. External site monitoring: E.g., tools that monitor if a site is down
6. Internal site monitoring: E.g., Bash scripts that track performance indicators
7. DNS optimization: Fast & reliable DNS providers like CloudFlare or Amazon Route 53
8. DNS Prefetching, preloading & preconnecting
9. Server: Distributed functionality. E.g.: external firewall, Varnish, load balancing
10. Server: Hardware & location
11. Server: Stack design. E.g.: Apache vs. Nginx, RDBMS, PHP version
12. Server: Apache: Directives at the most efficient location (global, site config files, .htaccess)
13. Server: In-memory vs. in-storage?
14. Internal caching: Transients, page caching, object caching, in-memory caching vs. database-cacing
15. External caching: External caching, Varnish? CloudFlare? CDN?
16. Traffic management (firewall?): Bot visits
17. Database optimization: Cleanup, query optimization, adding indexes, custom functionality
18. Traffic compression: Use e.g., GZip for sending files
19. Site: Heartbeat API control
20. Site: Asset optimization: Defer JavaScript
21. Site: Asset optimization: Asynchronous JavaScript loading
22. Site: Asset optimization: Asynchronous loading of third-party analytics tools
23. Site: Image size optimization
24. Site: Minification & concatenation
25. Site: Reduce number of HTTP requests (?)
26. Site: Plugins: Optimize amount & resources, document this, disable/delete plugins that are only needed incidentially
27. Site: Theme: Optimize theme. E.g.: custom vs. off-the-shelf
28. Site: Have a responsive theme with separate content optimizations for desktop & mobile
29. Site: Mobile-specific optimization: AMP (Accelerated Mobile Pages)
30. Site: Mobile-specific optimization: E.g., touch-friendly buttons, less content because of smaller screens, etc.
31. Site: Optimize security infrastructure. E.g.: WAF needed? If so, what? External firewall? Captcha, etc.
32. Site: Limit external services (fonts, ads, libraries?)
33. Site: WooCommerce: Number of taxonomies + elements, complexity of shop page, shop page caching
34. Site: WooCommerce: Number of products
35. Site: Speed perception: Optimize above-the-fold content
36. Site: Speed perception: Ensure quick user experience
37. Site: Speed perception: Don't use "wait screens"
38. Site: Speed perception: Lazy loading: Delay loading of non-essential images & iframes until they are needed
39. Browser caching

Sources

Some really nice sources, if this stuff is new to you:

• https://wordpress.org/support/article/optimization
• https://onlinemediamasters.com/slow-wordpress-site