Speed up WordPress websites

Having a fast and responsive website that works across device interfaces goes a long way in helping grow and retain business. Website speed is an important component to ensure visitor interest, encourage decision making, and deliver a good end-user experience. One of the major impacts of a slow performing website is that search engines will rank the site lower in the Search Engine Results Page (SERP) than the faster loading websites. Slower websites also lead to increased costs if more bandwidth is being used to transfer heavy objects on the internet, for storage, and for backups. To improve the speed of a website, we first need to know what usually slows a website.

Checking a WordPress website’s response speed using tools

Site24x7 is a tool that checks the performance speed of a WordPress website.

WordPress.com states “A WordPress.com baseline site on a Business plan with built-in custom plugins and a default theme activated, loads in around 1 second.” A good target time for a full-fledged website or webpage load is between one and three seconds. WordPress.com further mentions that “4 to 5 seconds is the time that a site takes to load on average, across the web.” As a good practice, optimizing pages and images will lessen time to load a page or site.

The above referred automated site performance tools provide a general perspective on improvement possibilities for a faster website response. For example, areas most tools touch upon include:

  • Time (in seconds) that it took for the website to fully load.
  • Total page size with information on images, videos, scripts, and other files loaded. Smaller the pages perform faster.
  • Requests: Shows the files needed to be loaded for the site to be displayed fully. The fewer requests, the fewer the files to load, resulting in faster site performance.
  • Some tools will show where the files are loaded from, how large they are, and how much time they take to load.

These tools are used to identify areas that could be improved, for example, larger sized pages and images, scripts, or external links taking too long to load.

Common reasons for slow website performance and their interventions

The leading cause for a slowly performing website is the size of the website and its components in KB:

Optimizing WordPress content
WordPress theme
  • The selected theme and the images added have a big effect on a site’s performance. The smaller (measured in KB) the theme and images, the faster the website will load for the visitor.
  • External scripts such as advertisement spots, videos, and font loaders too could slow down the site if incompatibilities exist or performance from the source is slow
Image size
  • Images are part of building up the brand and communication of a website. Images and can be included in posts, blogs, and individual pages. Optimizing these images by using external image compression tools and third-party plugins that help in optimizing or compressing images helps speed up performance and search engine rankings. Tools exist to help resize, condense, and optimize images in standard formats like JPG, GIF, PNG.
  • Manage loading speeds for images using approaches like Lazy-Load, where only the images seen in the browser window are downloaded at first. As the visitor scrolls, the remaining images are downloaded. This improves the user experience, since the site loads only the portion being viewed.
Compression
  • Compression technologies like GZIP compression compress content files like HTML, CSS, and JavaScript when responding to a user’s browsing request. The user’s browser receives compressed files quicker due to lower file size. These compressed files are uncompressed by the user’s browser and displayed. Most browsers support this technology.
Minimize CSS, HTML, and JavaScript files
  • A website’s theme contains Cascading Style Sheets (CSS), which describes how HTML elements are to be displayed on visual interfaces like screens. It's not unusual for HTML and CSS coding to have gaps known as white spaces, block limiters, unused characters, and symbols. A browser reads this incoming data, extracting instructions to display the webpage. Not having these spaces, unused symbols, and characters reduces the time to read the information, speeding up website response.
Web hosting configuration

There could be issues with the physical hosting. Hosting could be:

Shared
  • A shared host server supports several websites. While this provides the most cost-effective way to get started, there is not much possible by way of one website admin being able to manage or improve web-server settings to improve performance. Possible interventions in this scenario are caching, WordPress performance, and content offloading.
Virtual or dedicated server
  • In this setup one has control over the server settings. Having control over the physical server allows for server optimization along with caching, WordPress performance, and content offloading. If traffic load is high, additional virtual or physical dedicated servers could be added to move components like WordPress databases and site images to a different server. With minor updates to the configuration file, the new servers could become part of the website operation. More complex implementations using automated load balancers that replicate and partition resources to improve performance are possible, too.
Hardware performance
  • The physical hardware impacts performance, too. Having multiple high-speed processors, memory, solid state devices/disks, disk storage capacity, and higher internet bandwidth are important for faster processing and performance. For example, when loads increase on a server, higher processor speed and memory can help process page requests quickly. Higher memory and speedy storage can help to cache pages and page requests, ensuring that the website systems are not overwhelmed.
Other infrastructure factors that could impact performance
  • Location of server and visitors could have implications. If both are geographically distant from each other, internet performance could impact the user experience. This could be addressed by using a CDN. These mirror static files (including images) and keep them on CDN servers in selected geographic regions served, resulting in improved performance.
Minimizing Plugins
  • Suboptimal code in plugins can slow down a site. Most HTTP page requests come from plugins, and every installed plugin adds a bit of weight to the site. Only enable plugins that are being used, and disable or delete other plugins.
  • Plugins use server resources. The more plugins that are enabled, the more computing resources are needed. Monitor resource needs and ensure that resources are rationed appropriately.
  • In case a plugin is suspected to be slowing down a site, a trial approach could be considered: disable one plugin at a time and check performance. Sometimes a combination of plugins may be fighting for resources, slowing down the site.
  • Keep plugins updated with latest versions and patches. Work with plugin support desks and user forums in case the plugin is important but appears to slow down the site.
Keep it trim
  • WordPress database size tends to grow over time, as comments and revisions continue to remain stored. Remove unused themes and plugins from the database and perform regular maintenance tasks, including purging of unused tables.
  • External scripts may slow down performance due to data loading or accessing external sources to execute code. Reduce or avoid external scripts where possible. Suboptimal code in scripts could slow down a site.
  • Disable unused features like pingbacks and trackbacks, which are features used to alert users about a link being received on a blog or page.

Some WordPress speed optimization plugins

WP Super Cache by Automatic is a free plugin and includes a number of caching features that speed up websites. These include gzip compression, page cache, cache preloading, CDN support, advanced cache preload, and more.

  • It includes a comprehensive settings section with a separate tab to help with setup
  • An advanced settings area where configuration options include:
    • Gzip compression
    • Browser caching
    • How to cache content
    • How often to update the cache
    • It also includes a feature to let you preload content into the cache along with a tool to help you connect to a CDN of your choice
WP Super Cache details: https://wordpress.org/plugins/wp-super-cache/
  • Version: 1.7.2
  • Active installations: 2+ million
  • WordPress version: 3.1 or higher
  • Tested up to: 5.7
  • PHP version: 5.2.4 or higher
  • Languages: 28
WP Fastest Cache is a caching plugin that can enable page caching with the check of a box.
The free version supports
  • Gzip compression
  • Browser caching
  • Basic minimizations for HTML and CSS (but not JavaScript)
  • Option to disable WordPress emojis
  • Rules to exclude certain users and content from caching
  • A tool to help you integrate with CDNs
The Premium version offers more optimization features:
  • Image optimization
  • Database optimization
  • More advanced minimization, including support for JavaScript minimization.
  • A tool to eliminate render-blocking JavaScript resources.
  • Option to load Google Fonts asyncronously
  • Lazy loading
WP Fastest Cache details: https://wordpress.org/plugins/wp-fastest-cache/
  • Version: 0.9.1.6
  • Active installations: 1+ million
  • WordPress version: 3.3 or higher
  • Tested up to: 5.7
  • Languages: 34
W3 Total Cache

W3 Total Cache by BoldGrid is a feature-rich caching plugin. Expects users to be at a level higher than beginner to get most out of the tool. Allows control of many caching aspects on a site.

  • W3 Total Cache helps with file minimization and connection to a CDN of choice.
  • W3 Total Cache (W3TC) improves the SEO and user experience of a site by increasing website performance and reducing load times by leveraging features like content delivery network (CDN) integration.
  • Key features:
    • Page caching
    • Browser caching
    • Database caching
    • Object caching
    • Fragment caching
    • Accelerated Mobile Pages (AMP) support
    • Secure Socket Layer (SSL) support
    • Minimize CSS, JavaScript, and HTML with granular control
      • Minimization of posts and pages and RSS feeds
      • Minimization of inline, embedded, or third-party JavaScript with automated updates to assets
      • Minimization of inline, embedded, or third-party CSS with automated updates to assets
    • Support lazy load
    • WP-CLI support for cache purging, query string updating, and more
  • Tested up to: 5.7
  • Languages: 34
W3 Total Cache by BoldGrid details: https://wordpress.org/plugins/w3-total-cache/
  • Version: 2.1.1
  • Active installations: 1+ million
  • WordPress version: 3.8 or higher
  • Tested up to: 5.7
  • PHP version: 5.3 or higher
  • Languages: 16
LiteSpeed

LiteSpeed Cache for WordPress (LSCWP) is an all-in-one site acceleration plugin featuring server-level cache and a collection of optimization features. LSCache accelerates dynamic content (in addition to PHP pages) with features very similar to those in Apache mod_cache, using customizable, native implementation within the LiteSpeed server, reducing page load and server load times.

General features:
  • Server-level full-page cache
  • Private cache
  • Edge Side Includes (ESI)
  • Image optimization
  • Crawler
  • CSS, JavaScript, and HTML minimization
  • CSS and JavaScript combination
  • HTTP/2 push
  • CDN support
  • Browser cache support
  • Lazy load images
  • Database optimization
LiteSpeed Cache for WordPress (LSCWP) details:
  • Version: 3.6.4
  • Active installations: 1+ million WordPress
  • Version: 4.0 or higher
  • Tested up to: 5.7
  • Languages: 21

Summary

Heavy website size impacts performance and creates a poor experience for a site visitor, which in turn negatively impacts growth in business opportunities and the brand. Reasons for slow performance of a WordPress website include infrastructure and software-related issues. Speed testing tools help provide an overview of areas that impacting load speed.