WordPress is one of the most widespread and easily customizable CMSs. However, it's pretty slow in the default configuration, especially, if the site has a lot of visitors and heavy content, or uses a complex theme. Moreover, since 2010 Google has used page load times as a factor in its search ranking algorithms.

Luckily, the flexibility of this CMS allows many methods to speed it up and lower the loading time of a website. You can check your website using online tools such as the ones below to track the website speed results after each step:

• Google Page Speed
• GTmetrix
• Pingdom

All these tools will provide insight on how your website loads and which parts of the website take more time to load than others (i.e. which need to be optimized). The Google Page Speed and GTmetrix tools are better for beginners since they show helpful tips on how the website can be optimized while Pingdom and WebPagetest have a more technical approach and will need more website development experience to understand.

Below we will look at some ways you can optimize a WordPress website. We recommend following these tips when building your website.

Also, most theme developers provide sample websites that show how the theme works and displays. Make sure to test these websites by using tools like Google Page Speed and GTmetrix when possible.

You will have an option to scan and optimize all images in Media library in bulk using the Scan for unoptimized images option:

Select Start optimizing after the scan is completed:

Gzip is the most popular and effective compression method today. If gzip compression is enabled for website content, it generally reduces the response size by about 70%. To gzip your website components, log in to your cPanel >> go to the Software section >> the Optimize Website menu.

W3 Total Cache, WP Super Cache are the most popular cashing plugins as well as OPcache and Autoptimize.

W3TC utilizes multiple techniques to improve performance, including:

WP OPcache resets all cache after upgrading. It reduces website load by storing the compiled PHP code in the memory. OPCache is bundled with PHP starting from 5.5 and supports both memory and file caching. The plugin improves PHP performance by storing script bytecode in shared memory.

To flush OPcache, click on the Flush PHP OPcache button. The notification about flushed cache will appear:

Navigate to the Settings >> WP OPcache to check additional options the plugin provides, such as General Settings and Statistics.

In the Statistics menu, you can check memory status, scrips, and configuration.
General Settings provides you with the option to flush cache automatically, precompile PHP files or remove the OPcache button from the top navigation menu bar.
You can flush PHP cache from this menu as well.

After choosing a needed option, click on the Save Changes button to apply the changes:

Autoptimize plugin concatenates all scripts and styles, minifies and compresses them, adds expires headers, caches them, and moves styles to the page head, and scripts (optionally) to the footer.

In order to clear cache, mouse over the Autoptimize option on the top menu and click on the Delete Cache button:

The WP Asset Clean Up plugin for WordPress can help you reduce the number of HTTP requests for your website, making your website pages load smoothly and quickly. The WP Asset Clean Up plugin prevents unnecessary styles and scripts from loading on your pages. It forces assets to load only on the pages where they are actually required. It also minimizes the HTML code of the actual page.

While checking websites using Google Page Speed, you may encounter one or more notifications with a red exclamation mark saying "Eliminate render-blocking Javascript and CSS in above-the-fold content". This means that none of the above-the-fold content on the page could be rendered without waiting for the resources to load.

This can be resolved by enabling additional Minify settings of the W3 Total Cache plugin.

To do so, you will need to access the General Settings tab of the plugin and set the Minify mode to Manual, like so:

Before you continue, make sure that the JS minify settings fields in the Minify menu are set to use the following settings:

Once done, you will need to add the corresponding JavaScript URLs provided by Google PageSpeed in the JS file management field, like so:

Perform the same steps for the CSS file management field filling in the CSS URLs on the same page:

That should be it! The notice "Eliminate render-blocking Javascript and CSS in above-the-fold content" shouldn’t appear if the steps above were completed in order.

Autoptimize plugin minifies the HTML code itself, making your page lightweight.

The plugin is used for JS/CSS optimization. Also, there are advanced options available that allow you to tailor Autoptimize to your website’s specific needs.

Autoptimize is compatible with WP Super Cache which provides a more developed rewrite functionality. Go to the Autoptimize Settings to find the option for website optimization:

• JavaScript Options can be used for combining JavaScript files for your WordPress website to one file.
• CSS Options allow you to encode small images into your CSS files, put some CSS in the HTML file, etc.
• HTML Options let you manage HTML and opt to keep comments in place.
• CDN Options is useful if you are using CDN for some files. Add them to the CDN Base URL in this case.

Using Images tab, you can optimize images by compressing them.
Extra and Optimize More provide you with the additional settings and services that can be used for website optimization.

In order to check advanced options, click on Show advanced settings button:

In the appeared menu, you will see the more detailed options for website optimization:

After choosing the options needed, scroll down to the bottom of the page and press the Save Changes and Empty Cache button to save the modifications:

We would also like to remind you to back up the database and/or the whole website before making any major adjustments, especially to third-party plugins.