Caching the pages is one of the most effective methods for speeding up the site as well as reducing the load on the server. WP Super Cache is one of the most popular plugins for this purpose and the article overviews the plugin’s configurations.
The speed of the site is a significant factor affecting the ranking in the SERP. There are many methods to increase the speed of the site load but the most substantial result is usually achieved by setting up caching. For this purpose, one of the best plugins recommended – WP Super Cache.
The principle of work: Every time a visitor opens a page a lot of requests are sent to the server. It loads and transfers html, css and js files. The browser processes them and gives the user a loaded page. This process takes a while and since specific action is done for each visitor imagine when there are hundreds of them! Not every server will withstand such a load.
After activating and configuring the WP Super Cache plugin caching of the pages occurs at their first visit. Basically creating saved copies of pages in a separate folder on the server. All other visitors will be given a ready-made copy of the page and the server will receive a lot less new requests.
Site load speed can increase to 750% depending on many factors: your hosting, the theme, the number of plugins, pictures, etc. Usually, you can achieve the increase by 2-3 times. Also, if your resource is already mostly optimized, that growth may be smaller and vice versa.
For the plugin to work properly, it is necessary that the wp-content folder has 755 permissions. You can use an FTP client, for example FileZilla.
- Find wp-content folder – usuall way is: www -> Your domain -> wp-content.
- Click on it with the right mouse button -> the permissions to the file …
- In the column “numerical value” enter 755.
Also, you can contact hosting technical support and ask permission to install.
After activating the plugin go to “Settings -> WP Super Cache”.
Quick Setup WP Super Cache
To help those who do not want to go deep into every item. Below you can do the quick setup according to the screenshots. With these parameters, 95% of users should not have any problems with the plugin’s performance.
Expiry time and garbage collection settings:
This is not the most productive option but it saves time. Nevertheless, detailed settings below recommended.
Detailed Configuration of WP Super Cache Plugin
Start with enabling caching and click the “Update” button. After that, you can check whether the cache has been turned on.
Press the “Test Cache” button.
The result should be:
When everything is green its fine. If you have an error here (marked red) it doesn’t necessarily always mean that the plugin isn’t working. It just unable to check the time stamps of the pages, whatever the reason, although it is fully functioning.
If the cache test fails, try tweaking the Miscellaneous settings, specifically the “compress pages” and “cache rebuild” option.
If you see an old (cached) version of your page, delete cache:
In order to get the whole picture, go to the home page of your site and click the right mouse button anywhere -> View the page code (Ctrl + U) for Google Chrome. In other browsers something similar).
There should be comments from the plugin at the very end of the code:
Write in the comments, please, if you would not observe them. We will try to resolve the issue.
Enable Caching. Cache session views for easy access
Enabling caching if you disable the cache will not be created.
Expert. mod_rewrite usage for the cache maintenance
The fastest method. In order to use it, you need a server on Apache and you need to install the necessary modules: mod_rewrite, mod_mime, mod_headers and mod_expires. They are already installed by default in many cases. Write the request to your tech support to include the necessary modules if errors occur.
Unfortunately, not all virtual hostings can include this caching method, each provider has its own limitations. If you use a dedicated server (VPS) or a cloud VPS, there should not be any problems.
The interface of the WP Super Cache plugin looks more like as:
Simple does just fine for most websites.
Don’t cache pages for known users = Doesn’t show cached pages for regular visitors (they want to see new content).
Don’t cache pages with GET parameters = Doesn’t cache pages that are different for each of user.
Cache rebuild. Serve a supercache file to anonymous users while a new file is being generated = Shows cached page if file is in process being generated.
304 Not Modified browser caching. Indicate when a page has not been modified since it was last requested = Prevents updating cache on ‘tag’ pages (saves CPU).
Make known users anonymous so they’re served supercached static files = Shows cached pages for regular visitors (counters earlier setting ‘don’t cache pages for known users’).
Enable dynamic caching = Dynamic content (content that changes, eg. ads).
Mobile device support = If using mobile plugin like WPtouch, or mobile theme, this caches mobile pages.
Remove UTF8/blog charset support from .htaccess file. Only necessary if you see odd characters or punctuation looks incorrect. Requires rewrite rules update = If you see weird characters on your website this should fix it.
Clear all cache files when a post or page is published or updated = Clears cache to make sure new content it shown
Extra homepage checks = Mahes sure newest posts are shown on homepage.
Only refresh current page when comments made = Refreshes a post’s cache when a comments made.
Late init. Display cached files after WordPress has loaded = Allows content to stay dynamic (also fixes error ‘super cache dynamic page detected but late unit not set’).
/home/ – no need to change this.
3600 seconds is great for most websites can lower it to 1800. This is the frequency cached pages expire and are thrown away. If too slow, users never see the cached version. If too fast, it consumes lots of CPU.
Specify pages you don’t want to be cached (for example, eCommerce pages shoulf never be cached: account, checkout, cart, confirm order pages):
Prevents user agents (eg. Googlebot) from seeing cached pages:
Enable lock down = During lock down, new comments on a post will not refresh the cached static files. This will save server resources and help prevent your site drom crashing during a predivted traffic spike.
Add direct page = If you kbow a specific page will get a high spike in traffic, add them here.
Simple. PHP usage for the cache maintenance
Should be suitable for any site. Not as fast as the previous one but if it did not work with mod_rewrite use this one.
Self-explanatory – much easier and requires fewer server resources but then again less productivity.
Compress pages so they’re served more quickly to visitors.
Works only with mod_rewrite. Compresses the cache files (once!) and puts it in a separate folder on the server giving the user a compressed version already.
If you use GZIP compression or a plugin that implements it, you can still try to enable it. However, on a minority of site tried using this plugin, there was a compression conflict.
304 Not Modified browser caching. Indicate when a page has not been modified since it was last requested
Does not work with mod_rewrite. Each browser has its own cache. When you enter any page, it saves it in your memory. And the next time the page is reloaded, it’s faster already since the information is loaded from the browser’s memory. Enable if using PHP caching.
This item includes a check: did the page change at the last access to it? If not, the server sends a 304 error to the browser and loads it from the browser’s cache.
Do not cache pages for known users
Do not cache pages for visitors who have logged in before or left a comment at least. A useful point, if dynamic (often changing) information is being provided for logged-in users.
Do not cache pages with GET parameters (? x = y at the end of the URL)
If the site has a search for certain criteria enable it. For instance, a tourist site where there is a choice of the date of travel, mode of transport, duration, etc. After clicking the search button, it throws on the generated page whose url can look like this: “http: // domain / search? type1 = bus & days = 2 & max-price = 30”
Make known users anonymous so they’re served supercached static files.
Perceive all known users as anonymous. Cached pages will be given to everyone.
Clear all cache files when a post or page is published or updated
You could, of course, enable it but when there is an important often-changing information, it is better not since guests are not going to be able to see it in time.
Proudly tell the world your server can take any load (places a message in your blog’s footer)
Advertising the plugin in the footer. One can express gratitude to the author.
Enable dynamic caching. Requires PHP or simplified caching mode.
Works only with PHP and simplified caching.
Mobile device support.
If there is a separate mobile site theme or plugins implementing the mobile version, you must enable it. A separate mobile cache will be created.
If you use a responsive theme which adapts to the screen size, you do not need to turn it on.
Remove UTF8/blog charset support from .htaccess file
If there are odd characters on the pages or punctuation errors, turn it on.
Extra homepage checks. (Very occasionally stops homepage caching)
The author of the plugin is advising to enable this item when you observe the disappearance of the cache of any page. The phenomenon is rare but if there is a similar problem turn it on.
Only refresh current page when comments made
Removing the cache of the page where the comment was left, if moderation of the comments is on, will be updated after approval.
List the newest cached pages on this page
Not recommend since you can see all the pages in the “Cache Status” but more on this later.
Coarse file locking. You do not need this as it will slow down your website
It’s possible that the names of temporary files created by the plugin match. This incident leads to a server load. The chance of coincidence is very low.
Late init. Display cached files after WordPress has loaded
Item for developers. The initialization of the plugin takes place earlier than the full initialization of the WordPress API. If enabled, the cache will be given only after the full loading of WordPress. Disable.
DO NOT CACHE PAGE secret key
If there is a need to look at the page without a cache in doing so not cleaning it, you can use the “secret code”
After the sign “=” put in your code, please, written in the plugin’s settings.
When mod_rewrite was selected
It is necessary to make adjustments to htaccess in order for it to function and since the plugin does this automatically just click “Update rules mod_rewrite”
There will be a large window with a bunch of code, as always, if everything is green – everything is fine.
Expiry Time & Garbage Collection
Here you need to specify how often to clear the page cache. Recommended that you set the cache lifetime as long as possible.
Cache Timeout – the lifetime of the copy of the cache of the page, let’s say 604800 seconds. = 7 days, every seven days, a copy of the page becomes stale.
Scheduler – when to clear the cache, you can set the timer to N-sec or specify an interval
Notification Emails – send a message to e-mail every time the cache is automatically cleared.
To make it clear let’s have a couple of examples:
Online-store, everyday prices change, exactly at 00.00. You can set the cache lifetime for 12-20 hours and clear for each day at 00.01. Do not enable auto cache clear when a post or page is published or updated so that the information is always up-to-date.
A corporate site (having several pages), the information does not change at all. You can set the cache lifetime to 0 (zero) seconds and clearing is not important because the cache will not become stale. Thus, clearing will not be done.
If you set the cache copy time too short and the cleaning interval is too short also, the plugin will always update the cache which will cause a significant load on the server.
Accepted Filenames & Rejected URIs
Here you can prevent caching of certain types of pages.
Also below, you can add individual pages to exclusions.
You don’t need the exact path for adding. Just specify the fragment and all links that have certain URL fragment will not be cached.
Rejected User Agents
If it’s important that search bots receive up-to-date information about changes on the site. It’s best not to remove them from this list.
It is better to re-create the cache always when changing it. When scanning a site bot can cause a significant load. If you clear the list, the bots will receive cached pages and the load will decrease.
Restore Default Configuration
If you carefully read this article, then this paragraph should not be needed.
If the site is visited not only in the country where the server is located (hosting) the CDN connection will be a useful feature. This service is connected separately, there are plenty of services on the Internet, of course, it is paid.
Basic idea: Let’s say a site server is located in Germany, from Australia it will be loaded two to three times longer, due to distance. CDN is intended to create copies of the site files and place them on a server in Australia (different providers, different number of CDN points). Thus, visitors will receive data from the server closest to them.
Displays the statistics of pages in the cache and in this menu you can delete cached pages separately. The cache statistics are not generated in automatic mode, for this use the “Regenerate cache stats” button.
Delete cache – refreshes the cache in case you see old cached versions of your pages.
Differences WP-Cache vs WP-Super-Cache
The WP Super Cache plugin is based on the WP Cache plugin. In addition to standard caching the super cache creates saved copies of pages and gives them to visitors. Therefore, less requests are made to the server which results in faster loading.
Delete Expired – deletes the cache that has expired lifetime.
Delete Cache – deletes the entire cache on the site.
Here you can create a cache immediately without waiting for a visit to all pages of the site, as well as automate the procedure if necessary. Do not set the update interval too short, otherwise it will cause a heavy load on the server. Using this item creates a lot more files.
Some create the cache as needed and do not use automatic mode. After clicking the button “Preload Cache Now”, do not close the tab, the cache is created gradually, several pages every second. You can look in the new tab “contents” in real time as it appears.
WP Super Cache has third-party plugins that do not relate to site speed increase or caching, you can skip this section. But still here’s a couple of things.
If you plan to enable any plugin, you should consider two factors.
- Some of them work only in PHP caching mode.
- After updating WPSC plugins are deleted.
Not recommended to make changes to this section if everything works well.
Here you can enable debugging mode by specifying your IP in the appropriate field. Logs that can be found would be saved.
You can also enable the check of the front page, every 5 minutes. In rare cases, instead of the front page, you may be offered to download the archive in which the saved front page is located. Or it will be given a different page instead.
In the column Front page text, the key text must be added, a word or phrase that is contained only on the front page. If WPSC does not find the text it will notify by e-mail.
Uninstalling WP Super Cache
If you need to remove the plugin do everything in the following order:
On the “Easy” tab turn off caching and delete the entire cache.
Next, deactivate the plugin: