Of course the caching method you choose will produce greatly varying results in terms of the quality and impact on your site performance. So what\u2019s the best option?<\/p>\n
Continue reading, or jump ahead using these links:<\/p>\n
- \n
- All About That Cache<\/a><\/li>\n
- Why FastCGI Rules<\/a><\/li>\n
- Caching Policies<\/a><\/li>\n
- Plugin Possibilities<\/a><\/li>\n
- (Con)figuring it All Out<\/a><\/li>\n
- Your Cache Cow<\/a><\/li>\n<\/ul>\n
In this article, we\u2019re going to look more closely at what static server cache is, explain why we recommend FastCGI (with a peek into Static Server Cache FastCGI), and how implementing it can optimize your site speed and user experience.<\/p>\n
Let\u2019s get started.<\/p>\n
<\/a>All About That Cache<\/h2>\n
Rendering or fetching a page or post in WordPress requires queries to be sent back and forth from the database. A lot of these posts and pages won\u2019t be updated everyday.<\/p>\n
Rather than the server interpreting the site code itself, querying the database, and returning an HTML document back to the customer and finally loading the page, static caching saves a single result from the first two steps and provides that document to anyone else making the request.<\/p>\n
Static assets like CSS, JavaScript, and images are stored in browser caching, so the browser can retrieve them from its local cache. This is faster than downloading the resources again from the page’s server.<\/p>\n
Caching in WordPress has multiple benefits, the top amongst them being: speed and performance boosts<\/a>, hosting server load reductions, and more favorable rankings with search engines. As stated in prior optimization articles<\/a>, this will be affected by other metrics as well, as there are many components that factor into speed and performance.<\/p>\n
There are different caching modules, such as Varnish and FastCGI, along with different types of web servers, such as Nginx, Apache, and LiteSpeed. These modules and servers work in tandem to provide superior caching.<\/p>\n
![\"Caching](\"https:\/\/wpmudev.com\/blog\/wp-content\/uploads\/2021\/08\/001-logos-servers-modules-1050x938.png\")
Some modules and servers in the caching arena.<\/figcaption><\/figure>\n Varnish is a web application accelerator, also known as a caching HTTP reverse proxy. One of its key features is its configuration language, VCL. Offering great flexibility, VCL enables you to write policies on the handling of incoming requests, such as what content you want to serve, where you want to get the content from, and how the request or response should be altered.<\/p>\n
Nginx (pronounced Engine-X) started as a simple web server designed for maximum stability and performance, and has evolved into a multi-performance powerhouse, with capabilities to handle reverse proxy with caching, load balancing, WebSockets, index files & auto-indexing, FastCGI support with caching, and more. As the fastest\u2011growing open source web server, with more than 450 million sites dependent on their technology, Nginx is incredibly stable.<\/p>\n
We believe FastCGI, served by Nginx, is the cream of the crop. Read on for why.<\/p>\n
<\/a>Why FastCGI Rules<\/h2>\n
FastCGI\u2015an enhanced version of its predecessor, CGI (Common Gateway Interface)\u2015is a binary protocol for interfacing interactive programs with a web server. It\u2019s primary function is to reduce the overhead related to interfacing web server and CGI programs, allowing a server to handle more web page requests per unit of time.<\/p>\n
Instead of creating a new process for each request, FastCGI uses persistent processes to handle a series of requests.\u00a0Using Nginx FastCGI, when a user visits the same WordPress page as they did prior, your website will not perform the same PHP and database requests again because the page is already cached and served by FastCGI. Thus, users will have a much faster server response time after the initial visit.<\/p>\n
You\u2019ll also have reduced PHP-FPM and MariaDB (MySQL) load, as well as lower CPU usage. And finally, your server will be able to handle more traffic with the same specs, enabling you to better meet more demanding needs.<\/p>\n
For a visual on how these elements work together for superior caching, see the infographic below. (We\u2019ll talk about object caching in a bit.)<\/p>\n
![\"Browser](\"https:\/\/wpmudev.com\/blog\/wp-content\/uploads\/2021\/08\/002.0-how-website-serving-with-nginx-fastcgi-works-1050x481.png\")
Serving a browser request, using FastCGI and Memcached Object Cache.<\/figcaption><\/figure>\n All WordPress pages can gain huge benefits when using FastCGI.<\/p>\n
<\/a>Caching Policies<\/h2>\n
There are two content types to consider when setting your cache: static and dynamic.<\/p>\n
Static content is any file that is stored in a server and is the same every time it\u2019s delivered to users. Dynamic content changes based on factors specific to the user such as time of visit, location, and device.<\/p>\n
Social media pages are a good example of dynamic content. Twitter feeds look totally different for any given user, and users can interact with the content in order to change it (e.g., by liking, re-tweeting, or commenting).<\/p>\n
E-commerce sites are commonly heavy on dynamic content as well. With WooCommerce, for example, certain pages like Home, Shop, and single product pages can be fully cached. However, Cart, Checkout, and My Account pages should be excluded. You do not want to page cache these dynamic pages fully as the latest changes would not be seen.<\/p>\n
Dynamic web pages are not stored as static HTML files. Generated server-side, these typically come via origin servers, not from a cache. Since dynamic content can\u2019t be served to multiple users (as it\u2019s unique to each one), it\u2019s difficult to cache. However with advancements in technology, caching dynamic content is possible.<\/p>\n
One way to speed up dynamic web pages is to use dynamic compression. In this manner, the content still comes from the origin server instead of a cache, but the HTML files generated are made significantly smaller so that they can reach the client device more quickly.<\/p>\n
Just as page caching works on HTML page output, object caching works on your database queries. Object caching is a fantastic solution for caching dynamic content.<\/p>\n
Like the other caching components we discussed, there are several persistent object cache contenders in the field, the most well-known being Memcached, Redis, and APCu.<\/p>\n
As far as setting your caching policies goes, there isn\u2019t a one size fits all. However, what determines a more or less desirable static cache policy is basing it on the type of content your site is comprised of.<\/p>\n
For sites where user comments are steadily being added & approved (often by the minute), or frequent new content is the norm, you should structure your cache policy to clear more often, such as daily or even hourly.<\/p>\n
For content that is regularly updated, just not that often, a 30-day cache policy is more than enough.<\/p>\n
For static elements like logos, images, page fonts, JS, and core CSS stylesheets, you can extend the max age to one year.<\/p>\n
Even Google says<\/a> there\u2019s no one best cache policy, but they do offer some tips to assist in devising your caching strategy, beyond the scope of your static assets. These are:<\/p>\n
- \n
- Use consistent URLs<\/li>\n
- Ensure that the server provides a validation token (ETag)<\/li>\n
- Identify which resources can be cached by intermediaries (like a CDN)<\/li>\n
- Determine the optimal lifetime for each resource<\/li>\n
- Determine the best cache hierarchy for your site<\/li>\n
- Minimize churn (for a particular part of a resource that is often updated [e.g., JS function or set of CSS styles], deliver that code as a separate file)<\/li>\n<\/ul>\n
Popular site speed performance testers, GTmetrix<\/a>, consider resources cacheable if the following conditions are met:<\/p>\n
- \n
- It\u2019s a font, image, media file, script, or stylesheet<\/li>\n
- It has a 200, 203, or 206 HTTP status code<\/li>\n
- It doesn\u2019t have an explicit no-cache policy<\/li>\n<\/ul>\n
If you use a CDN like Cloudflare, you can set your cache policies through your account. Additionally, if you use our Hummingbird plugin, you can access these settings via the built in integrations for Cloudflare<\/a>.<\/p>\n
As a WPMU DEV hosted member, you can access the primary Static Cache settings through The Hub to enable the extremely efficient static cache policy.<\/p>\n
![\"DEV](\"https:\/\/wpmudev.com\/blog\/wp-content\/uploads\/2021\/09\/static-server-cache-1-1050x160.png\")
Turn on Static Server Cache from The Hub.<\/figcaption><\/figure>\n Ultimately, how you design your cache policy should be based on the type of content you serve, your web traffic, and any application-specific needs that exist for that new<\/em> new data.<\/p>\n
There are a number of tools you can use directly within WordPress that make implementing a static cache policy quick and easy. We\u2019ll look at those next.<\/p>\n
<\/a>Plugin Possibilities<\/h2>\n
A quick search for caching plugins on WordPress.org will return in excess of a thousand results. That\u2019s a lot of options to wade through. We handpicked a few that we believe to be solid options.<\/p>\n
Hummingbird<\/a><\/p>\n
\n![\"Hummingbird](\"https:\/\/wpmudev.com\/blog\/wp-content\/uploads\/2021\/08\/004.1-hummingbird-banner-1050x345.png\")
<\/div>\n<\/div>\nHummingbird is a one of a kind, world-class caching suite, active on more than +1 million websites.<\/p>\n
With Hummingbird\u2019s WordPress speed optimization, your pages will load faster, your search rankings and PageSpeed scores will be higher, and your visitors will be happier. In fact, speeding up your site has never been easier.<\/p>\n
Here is just a selection of HB\u2019s standout features: full Page, Browser, RSS, & Gravatar caching; performance reports; minify and combine Javascript, CSS, and Google Font files; GZIP compression for blazing-fast HTML, JS, and stylesheet transfer; configs (set & save your preferred performance settings, and instantly upload to any other site)\u2015and more.<\/p>\n
Hummingbird scans your site and provides one-click fixes to speed up WordPress in a flash. And it\u2019s completely free. (Consider Smush<\/a> as well; while not a static caching solution, it will compress and lazy load your images for marked speed improvements, and is also free.)<\/p>\n
WP Rocket<\/a><\/p>\n
![\"WP](\"https:\/\/wpmudev.com\/blog\/wp-content\/uploads\/2021\/08\/005-wp-rocket-banner-1050x336.png\")
<\/p>\nWith more than 1.5 million users, WP Rocket is a favored caching plugin for WordPress. It’s a premium service, which you can only install directly from their website.<\/p>\n
It\u2019s easy for non-techie users to understand, while more knowledgeable developers can customize it to their liking. It\u2019s compatible with many hosting providers, e-commerce platforms, themes, and other plugins.<\/p>\n
WP Rocket automatically starts caching your pages, without any need to tweak the code or mess with settings. Pricing starts at $49, for 1 website\/1 year.<\/p>\n
WP Super Cache<\/a><\/p>\n
![\"WP](\"https:\/\/wpmudev.com\/blog\/wp-content\/uploads\/2021\/08\/009-wp-super-cache-banner-1050x331.png\")
<\/p>\nWP Super Cache is from the team behind WordPress.com and WooCommerce… Automattic. This plugin is free, and has an astounding 2 million+ active installations.<\/p>\n
WP Super Cache serves cached files in 3 ways, which are ranked by speed. Expert <\/em>(the fastest), bypasses PHP by using Apache mod-rewrite to serve static html files. Simple <\/em>(mid-level speed, and the recommended way of using the plugin), uses PHP & does not require configuration of the .htaccess file, allowing you to keep portions of your page dynamic. WP-Caching mode<\/em> (the slowest), mainly caches pages for known users, and is the most flexible method.<\/p>\n
WP Super Cache comes with recommended settings, one of which is: If you\u2019re not comfortable with editing PHP files, use Simple mode.<\/p>\n
W3 Total Cache<\/a><\/p>\n
![\"W3](\"https:\/\/wpmudev.com\/blog\/wp-content\/uploads\/2021\/08\/006-w3-total-cache-banner-1050x331.png\")
<\/p>\nW3 Total Cache (W3TC) has over a million users, with an average rating of 4.4 out of 5 stars. It is a free plugin.<\/p>\n
W3TC improves the SEO and user experience of your site by increasing website performance, and reducing load times, leveraging features like CDN integration and the latest best practices.<\/p>\n
W3 Total Cache remedies numerous performance-reducing aspects of any website. It requires no theme modifications, modifications to your .htaccess<\/em> (mod_rewrite rules) or programming compromises to get started. The options are many and setup is easy.<\/p>\n
Some of W3TC features include: transparent CDN management with Media Library, theme files and WordPress itself; mobile support; SSL support; AMP support; minification & compression of pages\/posts in memory; and minification of CSS, JavaScript, and HTML with granular control.<\/p>\n
WP Fastest Cache<\/a><\/p>\n
![\"WP](\"https:\/\/wpmudev.com\/blog\/wp-content\/uploads\/2021\/08\/007-wp-fastest-cache-banner-1050x331.png\")
<\/p>\nWP Fastest Cache is another million+ user caching plugin.<\/p>\n
Setup is easy; no need to modify the .htaccess<\/em> file (it\u2019s done automatically). It\u2019s got a more minimal set of features, including SSL support, CDN support, Cloudflare support, preload cache, cache timeout for specific pages, and the ability to enable\/disable cache option for mobile devices. WP Fastest Cache is also compatible with WooCommerce.<\/p>\n
WP Fastest Cache is free, but offers a premium-for-pay version, which adds additional features, such as: Widget Cache, Minify HTML Plus, Minify CSS Plus, Minify JS, Defer Javascript, Optimize Images, Convert WebP, Google Fonts Async, and Lazy Load.<\/p>\n
LiteSpeed Cache<\/a><\/p>\n
![\"LiteSpeed](\"https:\/\/wpmudev.com\/blog\/wp-content\/uploads\/2021\/08\/008-litespeed-cache-banner-1050x340.png\")
<\/p>\nLiteSpeed Cache for WordPress (LSCWP) is an all-in-one site acceleration plugin, with more than 2 million active installations.<\/p>\n
It features an exclusive server-level cache and a collection of optimization features, such as: free QUIC.cloud CDN cache; lossless\/lossy image optimization; minification of CSS, JavaScript, and HTML; asynchronous loading of CSS; deferred\/delayed JS loading; and WebP image format support.<\/p>\n
LSCWP does require use with a web server (LiteSpeed, Apache, NGINX, etc.). It supports WordPress Multisite, and is compatible with most popular plugins, including WooCommerce, bbPress, and Yoast SEO.<\/p>\n
LiteSpeed Cache is free, but some of the premium online services provided through QUIC.cloud (CDN Service, Image Optimization, Critical CSS, Low-Quality Image Placeholder, etc.) require payment at certain usage levels.<\/p>\n
Ok, now that we\u2019ve covered some viable plugin options for caching, let\u2019s look at what you can do with the cache settings in WPMU DEV\u2019s hosting platform.<\/p>\n
<\/a>(Con)figuring it All Out<\/h2>\n
The best WordPress hosting providers\u2015leading in sales and racking up rave reviews\u2015have caching built in. Without it, they wouldn\u2019t be competitive enough in today’s market of tech-savvy web developers.<\/p>\n
If you\u2019re looking for tools that are integrated on managed WordPress hosting environments, WPMU DEV Hosting<\/a>, WPEngine<\/a>, Flywheel<\/a>, and Kinsta<\/a> all have caching built in. Quite frankly, the systems used by hosting companies are quicker and more effective than WordPress plugins.<\/p>\n
With WPMU DEV hosting, we use our own mega caching tool, Static Server Cache<\/strong>. This is page caching at the server level using FastCGI. Much faster than any PHP plugin, Static Server Cache greatly speeds up your site and allows for an average of 10 times more concurrent visitors.<\/p>\n
Understanding and managing the settings for caching in WPMU DEV hosting is an easy, hassle-free experience. C\u2019mon along and you\u2019ll see what I mean.<\/p>\n
From your WordPress admin page, go to WPMU DEV<\/strong>, Plugins<\/strong>, then click on The Hub<\/strong> icon.<\/p>\n
![\"Hub](\"https:\/\/wpmudev.com\/blog\/wp-content\/uploads\/2021\/08\/010-wp-dashboard-wpmu-dev-hub-1050x556.png\")
One-click access to the Hub from the WPMU DEV dashboard.<\/figcaption><\/figure>\n Next, from The Hub<\/strong> landing page, click on the site of your choice, under My Sites<\/strong>.<\/p>\n
![\"Listed](\"https:\/\/wpmudev.com\/blog\/wp-content\/uploads\/2021\/08\/011-hub-my-sites-click-a-site-1050x632.png\")
The Hub lists all of your hosted sites.<\/figcaption><\/figure>\n From here, click on either of the Hosting <\/strong>headers.<\/p>\n
![\"Hub](\"https:\/\/wpmudev.com\/blog\/wp-content\/uploads\/2021\/08\/012.0-the-hub-hosting-settings-1050x564.png\")
Two options to get to the hosting tools page.<\/figcaption><\/figure>\n Next you\u2019ll click on Tools<\/strong>, and scroll down to Static Server Cache<\/strong>. Click the Off <\/strong>button, then click Continue<\/strong> from the \u201cTurn on Static Server Cache\u201d popup window. (Note: Static Server Cache will be enabled by default for all new server\/hosting accounts created with us.)<\/span><\/p>\n
- Why FastCGI Rules<\/a><\/li>\n