Technical SEO Cheat Sheet #2: Reduce Page Load Time and Image Optimization

TL;DR: In this article we explore methods we can incorporate to reduce page load time as well as image optimization technical search engine optimization (technical SEO) along with several web image optimization best practices. We cover the Google PageSpeed Module, the W3 Total Cache Pro plugin (for WordPress-based websites), along with a brief explanation of some basic performance tests conducted via the WebPagetest.org website.

In the article entitled “On Page SEO Checklist 2018 : A Comprehensive Guide on ‘How To Make Your Website SEO Friendly’” two of the nine numbered items pertain to website page load performance. Put in simple terms: people and search engine crawlers prefer to not wait around for your server to respond to a request for content. People won’t wait and the website will end up with a high bounce rate and that means no visitors for you; search engines may assume the website is experiencing heavy traffic and back off. A slow website will frustrate visitors and they’ll eventually spend their valuable time elsewhere.

There are a multitude of content management systems (CMS) available however the focus for this series of articles is on WordPress, which powers around ~ 27% of the Internet at the time of this writing.

Factors that can impact website page load times

Several factors can slow down a website and, as a precondition, we’ll assume that the connection between the server and the Internet is fast enough and that the server itself doesn’t have any issues. We are then left to focus on WordPress and either the NGINX or Apache web servers (others won’t be covered). In WordPress the plugins, JavaScript, CSS, and images will all impact the load time for a page; embedded videos can impact the load time for a page as well.

There isn’t much that can be done with the plugins aside from using only the minimum set of high-quality, required plugins. If a plugin results in a slow website, so much so that this appears on the performance radar, then it likely needs to be removed or the performance issue(s) need(s) to be resolved by modifying the code directly and that may not be possible if the plugin is proprietary, nor is this a good engineering practice.

The following two tools used in tandem should improve WordPress performance considerably in most cases: Google PageSpeed Module (GPSM) and the W3 Total Cache Pro plugin (W3TC) — we will take a look at several benefits and drawbacks in the following sections.

Google PageSpeed Module for Apache & NGINX: Upsides

GPSM:

Can optimize images on-the-fly and supports the webp image format — this is a significant benefit for websites that have many existing images.
Is open-source software and can be found on GitHub.
Is developed and maintained by Google for the purposes of improving website performance.
Works with both the Apache and NGINX web servers.
Can optimize CSS, JavaScript, etc.

Technical SEO using the Google PageSpeed Module for Apache & NGINX: Downsides

GPSM:

Requires direct access to the server or VM.
Is not easy or straightforward to set up.
Requires repeat testing (see WebPagetest.org, for example) to ensure that changes to settings are having the desired effect.

Technical SEO using the W3 Total Cache Pro plugin for WordPress: Upsides

W3TC:

Delivers powerful caching along with a long list of options.
Can be used to optimize CSS, JavaScript, etc.
Works with various content delivery networks (CDNs).
Includes options such as security header settings which can be tested on securityheaders.com

I recommend starting with the free plugin and later graduate to the pro version when appropriate.

Technical SEO using the W3 Total Cache Pro plugin for WordPress: Downsides

W3TC Pro:

Requires a license.
Is not exactly easy or straightforward to set up.
Requires repeat testing (see WebPagetest.org, for example) to ensure that changes are having the desired effect.

Test page load times with WebPagetest.org

In this section, we demonstrate how to use the WebPagetest.org website to test changes made to a WordPress website that is using both W3 Total Cache and Google PageSpeed.

The image below (SEO_CS_2_WPT_1.png) includes pointers to two concerns: the grade at the top right, in green, indicates some important performance considerations which are enabled and work well. Note that the blue arrow points to the page load time, which should be lower once performance improvements have been implemented.

Technical SEO Test results from the WebPagetest.org website with pointers to the overall score and the page load times performance results. — WebPagetest.org is integral to performance engineering and Technical Search Engine Optimization (Technical SEO).

In the image below (SEO_CS_2_WPT_2) we observe that images are returned in webp format and that these images are also served via the CDN.

WebPagetest.org Waterfall View test results. — Technical SEO performance test results waterfall view with webpagetest.org.

Conclusion

A multitude of methods exist to help improve website performance so if you know of alternative solutions and feel like sharing them, please add your thoughts to the comments section below and we can discuss them — include your performance before and after too if you have them.

Finally, Amazon Web Services has a number of options for deploying a WordPress website which I’d like to try eventually — if you’ve been down this path already, add a comment explaining what you used and what the performance metrics look like.

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