Optimizing WordPress Performance with Plugins

Introduction

The very idea of using plugins to speed up the load times of a WordPress website or blog is counterintuitive, given that bloated plugins are often identified as the main reason a site performs too slowly. An entire cottage industry has evolved to address WordPress performance issues, along with a raft of plugins designed to monitor site performance and recommend strategies for improvement.

WordPress author awareness of the importance of minimizing page load times is on the rise, as studies continually show the number of seconds visitors are willing to wait before surfing elsewhere dropping year over year. Some experts now say a wait as long as 400 milliseconds—less than half a second—is enough to send visitors away, and a page load time a quarter of a second briefer than one’s competitors now constitutes an actual advantage on the web. Google now docks SEO points from slow sites, pushing them lower in hit lists.

Selectively deactivating installed plugins and then measuring any change in performance is a tried-and-true method for identifying performance-robbing plugins, which can then be uninstalled. After that, WordPress authors seeking quicker loads often try theme optimization, various caching strategies, or the adoption of a content delivery network.

But as a content management system (CMS), WordPress’s very reason for existence is convenience. Improving site performance simply by installing a plugin is an attractive and practical solution for many WordPress authors who want better performance but do not want to apply great amounts of time, effort or money to achieve it.

With that in mind, this article describes three ways to dramatically improve WordPress performance by doing nothing more than installing a plugin and choosing a few settings. All three plugins described are available from the WordPress Plugin Directory at http://wordpress.org/plugins/.

Loading Images Faster

Studies have shown that as many as 90 percent of WordPress sites are slowed chiefly by unoptimized images: picture files that contain excess metadata or are larger than necessary for how they are used in the layout. Many authors find that optimizing images is second only to cleaning out plugins as the quickest fix for a slow WordPress site.

Optimization isn’t the only approach to improving picture load times. Pros advise favoring images in the PNG format for icons and logos because of PNG’s transparency support, and favoring the JPEG format—and its typically smaller file sizes—for photographs. Using images first resized to the proper dimensions outside of WordPress helps, too; scaling them inside WordPress reduces dimensions but not file size.

But WordPress authors favoring a plugin optimization solution can look to tools like Prizm Image’s plugin for WordPress. Prizm Image is a free cloud service that applies patented technology to images to cut their files down to as little as a third of the original size while preserving the full resolution, display/print dimensions and image quality of the original image file. The service works on JPEG, PNG and GIF files.

The plugin for Prizm Image adds a single panel under the Media tab and some settings on the Media settings page to WordPress that enable the author to remove extraneous metadata and reduce file sizes for selected images in the author’s WordPress media library. The plugin can be configured to automatically apply these optimizations to all new images uploaded to the library, so every new image the author drops into a WordPress site is already as small and speedy as it can be.

Caching Pages for Faster Loading

As with image optimization, there are many different ways to enable caching of WordPress pages to speed up load times, some requiring more time and technical skill than others. But among the simple, plugin-based solutions is WP Super Cache, a static caching plugin.

The Super Cache plugin takes a dynamic WordPress site and uses it to generate static HTML files that load quickly and bypass the usual WordPress PHP script processing that can degrade performance.

The cached pages are served not to all visitors at all times, but rather to visitors who won’t notice the difference from the dynamic pages, such as those who aren’t logged in, those who have not left a blog comment or those who have not viewed a password-protected post. But by swapping in the HTML pages even for just these visitors, the plugin can trim server load and speed up performance for all visitors, even those viewing the regular WordPress PHP content.

Compressing JavaScript and CSS

Script files typically contain both unnecessary characters and extra space—useless bytes that slow down script loading and processing. Minification is a technique for speeding up script processing by removing unnecessary characters from code without changing the code’s function.

WP Minify is a plugin that applies minification to JavaScript and CSS code in a WordPress site by integrating an online Minify engine with WordPress. Just as the Prizm Image plugin boosts performance by shrinking image files without affecting their appearance, WP Minify improves performance by shrinking JavaScript and CSS content without affecting its function.

In effect, after installation the WP Minify plugin grabs script content from generated WordPress sites and passes it to the Minify engine, which returns consolidated, minified, compressed code that trims page load times considerably.

Conclusion

This brief article only scratches the surface of available WordPress extensions that can have a significant positive performance effect in a variety of ways. For example, there’s a free WordPress plugin for the Prizm Cloud service that enables authors to embed a fast, powerful document viewing window in a WordPress page so visitors can view PDF documents, slideshows and other document content quickly, without downloading the file or loading an external reader or application program.

No doubt the very best WordPress performance will be achieved by those authors willing to brave digging into the bowels of MySQL or direct editing the PHP code. But doing so tends to run against the WordPress culture, where authoring is meant to be simple and problems are meant to be solved by plugins. Many authors will likely be happy with the gains they can achieve with the installation of a few simple performance-enhancing plugins. For them, the hardest part may be choosing which plugins to apply.