Caching is a technique that can improve the performance of your web page by transparently storing data such that future requests for that data can be served faster. Caching your WordPress blog can effectively optimize the performance of your blog even during high traffic peaks.
When caching is enabled on your blog, only the first visitor goes through the series of processes such as processing of PHP code, making calls to the database and finally displaying the HTML output. The final output is saved as a static file and is used to serve subsequent requests. This improves the page loading time significantly and also reduces the server load.
There are a lot of caching plugins available for WordPress. Below are some of the most effective caching plugins for WordPress.
2. WP Cache – WP Cache is an extremely efficient caching plugin. It caches the WordPress pages and stores them as static file for serving future requests rather than loading and compiling the entire PHP code. It enables you to set the expiration time for the static pages, define rules for accepting and rejecting which files should be cached and also manage the cached files.
3. 1 Blog Cacher – This plugin caches your WordPress pages and stores the cached files in organized directories emulating the URL’s, making it easy to manage them. It enables you to set the expiration time for the cached files and also allows you to delete all the cached files or just the expired ones. Cached files are updated whenever new posts or comments are published, edited or deleted.
4. Hyper Cache – Hyper Cache enables you to cache the entire HTML output of the pages to files and also enables you to cache 404 pages and redirects. It reduces the disk space usage by using compressed storage and also auto-cleaning the system. It is very easy to use and can manage both plain and gzip compressed pages.
6. WP Super Cache – WP Super Cache is a fork of WP Cache plugin. WP Super Cache caches your WordPress pages and serves future requests directly from the cached file without even loading the PHP engine whereas WP Cache requires the PHP engine to be loaded. Thus, this plugin can optimize the performance of your blog even during high traffic.
7. Hot Linked Image Cache – This plugin automatically caches hot linked images in your WordPress posts locally. It also gives you the option to cache specific posts by specifying the post id. This plugin works on any server running PHP as it supports both furl and allow_url_fopen.
8. Optimize DB – This plugin runs an optimize_table command on your WordPress tables, effectively defragmenting it. It is very useful for tables that are frequently updated. This plugin is very easy-to-use and the interface contains only a single button and some info on how much space will be saved.
9. WordPress Clean Options Plugin – This plugin detects redundant options in your WordPress database and enables you to delete them safely. It gives you an easy and safe way to clean up your wp_options table, thereby improving the performance of your blog. It also has many inbuilt safety features that prevents you from accidentally deleting the wrong entries.
10. DB Cache – This plugin has a different method of caching. Instead of caching the HTML output to file, this plugin caches WordPress’ MySQL queries to a file. Thus, it uses very less disk space for caching and also optimizes the performance of your blog significantly.
Update: DB Cache is no longer up to date, check out DB Cache Reloaded instead.
11. Throttle – Throttle enables you to implement bandwidth and scripting limiting on your blog. It can be really handy during high traffic peaks. It tries to prevent the non-critical elements of your blog from loading, thereby improving the overall performance of your blog.
12. CSS Cache Buster – CSS Cache Buster is a simple but powerful plugin. It is a really great plugin for developers as it displays the changes in your CSS immediately. It ensures that your WordPress blog delivers the latest version of your CSS stylesheet to your visitors.
13. WP Widget Cache – This plugin enables you to cache the output of your blog widgets. It enables you to set the cache time for each widget individually. This plugin cannot be used as a replacement for plugins like WP Cache and WP Super Cache, but can be used in addition with them.
14. WP Cache Users – WP Cache Users is a really useful plugin for a multi-author blog. This plugin automatically caches individual author’s data so as to reduce the number of database queries each time a post or comment page is viewed.
15. Cache Time – This plugin enables you to display the time of caching of the current page. The time zone of the WordPress blog and whether caching is enabled on that page is also taken into account. It also enables you to easily customize the display text when the page is cached, no cache is present and also the date format.