What is Cache? Top 5 Best Cache Plugins to Speed Up Your WordPress Site
Last Updated: October 1, 2020 in Review
The website speed is one of the most important elements that affect user experience. Therefore, webmasters always care about speeding up their website. Using cache plugins is one of the most popular and easiest ways to do it.
In this article, I made a list of the top 5 best cache plugins to speed up your WordPress sites. Let’s spend 5 minutes reading it and choosing the most suitable one for your website.
What is Cache?
Normally, to display a website, the browser has to send requests to the website server to retrieve data by the following process:
- The browser sends requests to the web server
- After receiving requests, the web server finds and processes data
- The web server sends data to the browser
- The browser receives data and displays them
This process will be repeated every time the browser needs to retrieve data from the web server. Therefore, people use cache to save time.
Cache is a technique to speed up the process that retrieves and sends data to the browser to display. Data is created once and re-used all the time later, thereby reducing the server load.
Cache may be created and saved in these locations:
- Browsers
- Proxy servers
- The website server
Benefits of Using Cache
Using cache will increase the data displaying speed and reduce the server load. The high loading speed will improve the user experience and conversion rate, thereby bringing benefits for the website owner.
Besides, Google will highly appreciate and score your website when it has a higher loading speed. It will increase the opportunity to display your website on top of SERPs and gain more organic traffic.
Popular Cache Techniques
These are the most popular cache techniques:
HTML Cache (Page Cache)
HTML Cache is the most famous cache technique because it’s simple and effective. The website data will be saved as a static HTML file. When the web server receives requests, it will send these HTML files to the browser instead of the usual process.
Database Cache
Database cache is a technique of storing cache files for all queries to the database. When there are any data requests from the database, the web server will use these cache files. It means that the usual stage of querying and processing data will be bypassed.
Because processing and querying data is often complicated and time-consuming (in fact, the database is often the bottleneck of the website performance) so that caching these queries to reduce the database load is very necessary.
Opcode Cache
Opcode cache technique is storing the results of processing PHP code to RAM and using them for the same subsequent requests. If the usual data processing is complex and time-consuming, this technique will speed up the process effectively.
Object Cache
This technique is about storing objects (which the queries to the database return) into the temporary memory (cache) on the server. It helps minimize the number of queries to the objects in the future. This technique is often combined with a cache software for servers such as Redis or Memcached.
Browser Cache
The browser has a temporary memory (cache) to store static data of the website such as pictures, media files, CSS / JS files, … Thanks to that, the browser can retrieve data from this cache memory and display it immediately without sending requests to the web server. It will save a lot of time.
Each Cache plugin may use one or combine some of these above techniques. However, after a quick review, I found out that almost the top popular cache plugins use the HTML Cache as the main technique.
Top 5 Best Cache Plugins
Among various of cache plugins out there, we took a review some and made a list of top 5 best cache plugins as follows:
- Litespeed Cache
- WP Super Cache
- W3 Total Cache
- WP Fastest Cache
- WP-Rocket
Litespeed Cache
Litespeed Cache is a powerful, feature-rich, and free plugin. It has an exclusive server to store cache (Cache is stored on this server instead of your web server). This plugin uses HTML Cache (Page Cache) as the main technique. In addition, you can configure to use object cache and browser cache. Besides, it’s compatible with popular plugins such as bbPress, Yoast SEO, WooCommerce, …
By comparison, this plugin achieved an impressive speed when compared to others (as image below). Therefore, it is most likely the best plugin for caching.
Note that Litespeed Cache is a kind of freemium plugin, you may want to upgrade to the premium to use more advanced features. However, the default features of its free version are relatively enough to use. Besides, Litespeed Cache plugin requires a Litespeed server. If your site doesn't run on it, you can't use cache features.
Highlight features
- HTTP/2 Push for CSS/JS (on web servers that support it)
- Combine CSS/JS
- Multiple CDN support
- Minify inline CSS/JS
- Lazyload images/iframes
- Browser Cache
- Database Cleaner and Optimizer
WP Super Cache
WP Super Cache is a free and easy-to-use plugin that uses HTML Cache technique. It’s especially suitable for medium and small websites. This plugin allows you to store cache for your website in a flexible way with 3 following levels:
- Simple: easy to customize and use, suitable for almost all websites.
- Expert: use for websites that have huge traffic at one time.
- WP - Cache caching: choose this level when you want to store cache for specific users such as someone signed in, left comments, or bought products on your site (users that visit the website frequently).
Highlight features
- Easy to use
- Compress pages
- Don’t cache pages for known users
- Cache rebuild
- CDN support
- Extra homepage checks
W3 Total Cache
W3 Total Cache is a freemium plugin with a lot of advanced features. It allows you to store cache for your website professionally using all the above cache techniques.
However, because this plugin has many advanced features and options so that it may be difficult to use for the beginners. But if you have the basic technical knowledge and want to challenge yourself and enhance your skills so that W3 Total Cache is a perfect solution.
Highlight features
- Caching statistics for performance insights of any enabled feature
- Compatible with shared hosting, virtual private / dedicated servers and dedicated servers / clusters
- Secure Socket Layer (SSL) support
- Accelerated Mobile Pages (AMP) support
- Transparent content delivery network (CDN) management with Media Library, theme files and WordPress itself
- Caching of (minified and compressed) pages and posts in memory or on disk or on (FSD) CDN (by user agent group)
- Mobile support: respective caching of pages by referrer or groups of user agents including theme switching for groups of referrers or user agents
- Caching of database objects in memory or on disk
- Reverse proxy integration via Nginx or Varnish
WP Fastest Cache
WP Fastest Cache is another easy to use and free plugin. In addition to HTML cache, it also supports browser cache.
This plugin has many useful features such as Preload Cache (Automatically create the cache for all the page), Enable/Disable cache option for logged-in users, Cache Timeout, … It also supports CDN, SSL, and Cloudflare.
WP Fastest Cache is a good choice for people that love simplicity because all the options are located in one tab of settings only.
Highlight features
- Mod_Rewrite which is the fastest method is used in this plugin
- All cache files are deleted when a post or page is published
- Admin can delete all cached files from the options page
- Admin can delete minified CSS and JS files from the options page
- Block cache for specific page or post with Short Code
- Cache Timeout – All cached files are deleted at the determined time
- Cache Timeout for specific pages
- Enable/Disable cache option for mobile devices
- Enable/Disable cache option for logged-in users
- Support CDN, SLL, Cloudflare
- Preload Cache – Create the cache of all the site automatically
- Exclude pages and user-agents
WP-Rocket
Last but not least is WP-Rocket. Unlike the others, this is a premium plugin. Obviously, it’s powerful, feature-rich, and quite popular. WP-Rocket runs on 2 main techniques that are page cache and browser cache.
WP-Rocket brings you useful features that are totally worth your money such as Preload Cache, Static Files Compression, Sitemap Preloading, Browser Caching, …
Along with caching, WP-Rocket also provides a lot of other features to speed up websites such as CDN, Lazy load, Cloudflare compatible, eCommerce friendly, Developer friendly, ... Because this plugin synthesizes many useful techniques (not only cache) so that many WordPress users love it.
Highlight features
- Quick Setup
- Page Cache (HTML Cache)
- Preload Cache
- Preload Sitemap
- GZIP Compression
- Browser Cache
- Multilingual Compatibility
- Lazy Load
- CDN
- Developer Friendly
- eCommerce Friendly
- Cloudflare Compatibility
Last Words
Hopefully, by this article, you chose a suitable plugin for your website. Apart from caching, there are many other techniques to speed up your site that you can learn more here. Good luck and don’t forget to follow our upcoming tutorials to gain more useful techniques about WordPress!