WP Super Cache vs W3 Total Cache

W3 Total Cache (W3TC) improves the SEO, Core Web Vitals and overall user experience of your site by increasing website performance and reducing load times by leveraging features like content delivery network (CDN) integration and the latest best practices. W3TC is the only web host agnostic Web Performance Optimization (WPO) framework for WordPress trusted by millions of publishers, web developers, and web hosts worldwide for more than a decade. It is the total performance solution for optimizing WordPress Websites. BENEFITS Improvements in search engine result page rankings, especially for mobile-friendly websites and sites that use SSL At least 10x improvement in overall site performance (Grade A in WebPagetest or significant Google PageSpeed improvements) when fully configured Improved conversion rates and “site performance” which affect your site’s rank on Google.com “Instant” repeat page views: browser caching Optimized progressive render: pages start rendering quickly and can be interacted with more quickly Reduced page load time: increased visitor time on site; visitors view more pages Improved web server performance; sustain high traffic periods Up to 80% bandwidth savings when you minify HTML, minify CSS and minify JS files. KEY FEATURES Compatible with shared hosting, virtual private / dedicated servers and dedicated servers / clusters Transparent content delivery network (CDN) management with Media Library, theme files and WordPress itself Mobile support: respective caching of pages by referrer or groups of user agents including theme switching for groups of referrers or user agents Accelerated Mobile Pages (AMP) support Secure Socket Layer (SSL/TLS) support Caching of (minified and compressed) pages and posts in memory or on disk or on (FSD) CDN (by user agent group) Caching of (minified and compressed) CSS and JavaScript in memory, on disk or on CDN Caching of feeds (site, categories, tags, comments, search results) in memory or on disk or on CDN Caching of search results pages (i.e., URIs with query string variables) in memory or on disk Caching of database objects in memory or on disk Caching of objects in memory or on disk Caching of fragments in memory or on disk Caching methods include local Disk, Redis, Memcached, APC, APCu, eAccelerator, XCache, and WinCache Minify CSS, Minify JavaScript and Minify HTML with granular control Minification of posts and pages and RSS feeds Minification of inline, embedded or 3rd party JavaScript with automated updates to assets Minification of inline, embedded or 3rd party CSS with automated updates to assets Defer non-critical CSS and JavaScript for rendering pages faster than ever before Defer offscreen images using Lazy Load to improve the user experience Browser caching using cache-control, future expire headers and entity tags (ETag) with “cache-busting” JavaScript grouping by template (home page, post page etc) with embed location control Non-blocking JavaScript embedding Import post attachments directly into the Media Library (and CDN) Leverage our multiple CDN integrations to optimize images WP-CLI support for cache purging, query string updating and more Various security features to help ensure website safety Caching statistics for performance insights of any enabled feature Extension framework for customization or extensibility for Cloudflare, WPML and much more Reverse proxy integration via Nginx or Varnish Image Converter extension provides modern image format conversion (e.g., WebP, AVIF) from common image formats (on upload and on demand) W3 Total Cache Pro Features With over a million active installs, W3 Total Cache is the most comprehensive WordPress caching plugin available and has robust premium features that help deliver an exceptional user experience. Full Site Delivery: Serve your entire site from a Content Delivery Network (CDN), ensuring faster load times worldwide. Fragment Cache: Optimize the caching of dynamic content while still improving performance. REST API Caching: Speed up your headless WordPress site by caching REST API calls. Eliminate Render-Blocking CSS: Ensure your CSS doesn’t hold up page loading, providing faster initial paint. Delay Scripts: Improve performance by delaying the loading of non-essential scripts until they are needed. Preload Requests: Boost page performance by preloading critical resources before they’re requested. Remove CSS/JS: Clean up unnecessary CSS and JavaScript files that slow down your pages. Lazy Load Google Maps: Load Google Maps only when it’s visible, reducing unnecessary requests. WPML Extension: Optimize performance on multilingual sites powered by WPML. Caching Statistics: Get detailed insights on cache usage and performance improvements. Purge Logs: Keep your site clean by automatically purging unnecessary cache logs. 30-Day Money-Back Guarantee Try W3 Total Cache Pro risk-free with our 30-day money-back guarantee. If you’re not satisfied, we will refund your purchase. PAGESPEED SCORE IMPROVEMENTS To help you understand the impact of individual features on your website’s performance, we’ve tested each feature separately to see its effect on Google PageSpeed scores. While optimal results come from configuring several different caching tools together, the following individual features also show significant improvements on their own: Remove Unused CSS/JS This feature removes CSS and JavaScript files that are not needed for the current page, reducing the load time. Added over 27 points to the Google PageSpeed score (Before: 57.2 / After: 86.7) Reduced the Potential Savings From Unused JavaScript from 127.5 KiB to 84 KiB View the test results Full Site Delivery Full Site Delivery optimizes the delivery of your entire site, enhancing the server response time. Added a 99% performance enhancement to the Average Server Response Time (Before: 3413 ms / After: 34 ms) View the test results Eliminate Render Blocking CSS This feature eliminates CSS that blocks the rendering of your page, speeding up the initial load time. Added over 17 points to the Google PageSpeed score (Before: 53.75 / After: 71) Reduced the Potential Savings From Render-Blocking Resources by over 94% (Before: 2432.5 ms / After: 125 ms) Improved the Largest Contentful Paint time by over 56% (Before: 7s / After: 3.04s) View the test results Delay Scripts Delay Scripts postpones the loading of certain scripts until they are needed, reducing initial load times. Added 14 points to the Google PageSpeed Performance score (Before: 54.25 / After: 68.5) Reduced the Time Third-Party Code Blocked The Main Thread For by 62% (Before: 825 ms / After: 197.5 ms) View the test results Rest API Caching This feature caches API responses, reducing server load and speeding up API interactions. Reduced the Average Server Load by 40% (Before: 0.62 / After: 0.37) Sped up API Responses by 84.5% (Before: 968ms / After: 150ms) Reduced the Average Server Load by 24% under during a major traffic spike (Before: 34.55 / After: 26.19) View the test results Modern Image Formats Converts images to modern formats like WebP or AVIF, which are more efficient and faster to load. Added over 9 points to the Google PageSpeed score (Before: 84.67 / After: 93.83) View the test results Lazy Load Google Maps Delays the loading of Google Maps until the user interacts with them, reducing initial load time. Added 10 points to the Google PageSpeed score (Before: 66 / After: 76) Reduced the Total Blocking Time Performance score by 72% (Before: 287.5 ms / After: 80 ms) View the test results Speed up your site tremendously, improve core web vitals and the overall user experience for your visitors without having to change your WordPress host, theme, plugins or your content production workflow. What users have to say: Read testimonials from W3TC users. Who do I thank for all of this? It’s quite difficult to recall all of the innovators that have shared their thoughts, code and experiences in the blogosphere over the years, but here are some names to get you started: Steve Souders Steve Clay Ryan Grove Nicholas Zakas Ryan Dean Andrei Zmievski George Schlossnagle Daniel Cowgill Rasmus Lerdorf Gopal Vijayaraghavan Bart Vanbraban mOo [villu164] (https://www.wordfence.com/threat-intel/vulnerabilities/researchers/villu164) Please reach out to all of these people and support their projects if you’re so inclined.

This plugin generates static html files from your dynamic WordPress blog. After a html file is generated your webserver will serve that file instead of processing the comparatively heavier and more expensive WordPress PHP scripts. The static html files will be served to the vast majority of your users: Users who are not logged in. Users who have not left a comment on your blog. Or users who have not viewed a password protected post. 99% of your visitors will be served static html files. One cached file can be served thousands of times. Other visitors will be served custom cached files tailored to their visit. If they are logged in, or have left comments those details will be displayed and cached for them. The plugin serves cached files in 3 ways (ranked by speed): Expert. The fastest method is by using Apache mod_rewrite (or whatever similar module your web server supports) to serve “supercached” static html files. This completely bypasses PHP and is extremely quick. If your server is hit by a deluge of traffic it is more likely to cope as the requests are “lighter”. This does require the Apache mod_rewrite module (which is probably installed if you have custom permalinks) and a modification of your .htaccess file which is risky and may take down your site if modified incorrectly. Simple. Supercached static files can be served by PHP and this is the recommended way of using the plugin. The plugin will serve a “supercached” file if it exists and it’s almost as fast as the mod_rewrite method. It’s easier to configure as the .htaccess file doesn’t need to be changed. You still need a custom permalink. You can keep portions of your page dynamic in this caching mode. WP-Cache caching. This is mainly used to cache pages for known users, URLs with parameters and feeds. Known users are logged in users, visitors who leave comments or those who should be shown custom per-user data. It’s the most flexible caching method and slightly slower. WP-Cache caching will also cache visits by unknown users if supercaching is disabled. You can have dynamic parts to your page in this mode too. This mode is always enabled but you can disable caching for known users, URLs with parameters, or feeds separately. Set the constant “DISABLE_SUPERCACHE” to 1 in your wp-config.php if you want to only use WP-Cache caching. If you’re not comfortable with editing PHP files then use simple mode. It’s easy to set up and very fast. Recommended Settings Simple caching. Compress pages. Don’t cache pages for known users. Cache rebuild. CDN support. Extra homepage checks. Garbage collection is the act of cleaning up cache files that are out of date and stale. There’s no correct value for the expiry time but a good starting point is 1800 seconds. Consider deleting the contents of the “Rejected User Agents” text box and allow search engines to cache files for you. Preload as many posts as you can and enable “Preload Mode”. Garbage collection of old cached files will be disabled. If you don’t care about sidebar widgets updating often set the preload interval to 2880 minutes (2 days) so all your posts aren’t recached very often. When the preload occurs the cache files for the post being refreshed is deleted and then regenerated. Afterwards a garbage collection of all old files is performed to clean out stale cache files. Even with preload mode enabled cached files will still be deleted when posts are modified or comments made. Development Active development of this plugin is handled on GitHub. Translation of the plugin into different languages is on the translation page. Documentation If you need more information than the following, you can have a look at the wiki or the Developer documentation. Preloading You can generate cached files for the posts, categories and tags of your site by preloading. Preloading will visit each page of your site generating a cached page as it goes along, just like any other visitor to the site. Due to the sequential nature of this function, it can take some time to preload a complete site if there are many posts. To make preloading more effective it can be useful to disable garbage collection so that older cache files are not deleted. This is done by enabling “Preload Mode” in the settings. Be aware however, that pages will go out of date eventually but that updates by submitting comments or editing posts will clear portions of the cache. Garbage Collection Your cache directory fills up over time, which takes up space on your server. If space is limited or billed by capacity, or if you worry that the cached pages of your site will go stale then garbage collection has to be done. Garbage collection happens on a regular basis and deletes old files in the cache directory. On the advanced settings page you can specify: 1. Cache timeout. How long cache files are considered fresh for. After this time they are stale and can be deleted. 2. Scheduler. Setup how often garbage collection should be done. 3. Notification emails. You can be informed on garbage collection job progress. There’s no right or wrong settings for garbage collection. It depends on your own site. If your site gets regular updates, or comments then set the timeout to 1800 seconds, and set the timer to 600 seconds. If your site is mostly static you can disable garbage collection by entering 0 as the timeout, or use a really large timeout value. The cache directory, usually wp-content/cache/ is only for temporary files. Do not ever put important files or symlinks to important files or directories in that directory. They will be deleted if the plugin has write access to them. CDN A Content Delivery Network (CDN) is usually a network of computers situated around the world that will serve the content of your website faster by using servers close to you. Static files like images, Javascript and CSS files can be served through these networks to speed up how fast your site loads. You can also create a “poor man’s CDN” by using a sub domain of your domain to serve static files too. OSSDL CDN off-linker has been integrated into WP Super Cache to provide basic CDN support. It works by rewriting the URLs of files (excluding .php files) in wp-content and wp-includes on your server so they point at a different hostname. Many CDNs support origin pull. This means the CDN will download the file automatically from your server when it’s first requested, and will continue to serve it for a configurable length of time before downloading it again from your server. Configure this on the “CDN” tab of the plugin settings page. This is an advanced technique and requires a basic understanding of how your webserver or CDNs work. Please be sure to clear the file cache after you configure the CDN. REST API There are now REST API endpoints for accessing the settings of this plugin. You’ll need to be authenticated as an admin user with permission to view the settings page to use it. This has not been documented yet but you can find all the code that deals with this in the “rest” directory. Custom Caching It is now possible to hook into the caching process using the add_cacheaction() function. Three hooks are available: ‘wp_cache_get_cookies_values’ – modify the key used by WP Cache. ‘add_cacheaction’ – runs in phase2. Allows a plugin to add WordPress hooks. ‘cache_admin_page’ – runs in the admin page. Use it to modify that page, perhaps by adding new configuration options. There is one regular WordPress filter too. Use the “do_createsupercache” filter to customize the checks made before caching. The filter accepts one parameter. The output of WP-Cache’s wp_cache_get_cookies_values() function. WP Super Cache has its own plugin system, loaded before most of WordPress. Add your own plugin either by putting it in the wp-content/plugins/wp-super-cache-plugins directory, or by calling wpsc_add_plugin( $name ) with the full path to the plugin. The cookies used to identify “known users” can be modified with wpsc_add_cookie( $name ) and wpsc_delete_cookie( $name ). See plugins/searchengine.php as an example. Troubleshooting If things don’t work when you installed the plugin here are a few things to check: Is wp-content writable by the web server? Is there a wp-content/wp-cache-config.php ? If not, copy the file wp-super-cache/wp-cache-config-sample.php to wp-content/wp-cache-config.php and make sure WPCACHEHOME points at the right place. Is there a wp-content/advanced-cache.php ? If not, then you must copy wp-super-cache/advanced-cache.php into wp-content/. You must edit the file and change the path so it points at the wp-super-cache folder. If pages are not cached at all, remove wp-content/advanced-cache.php and recreate it, following the advice above. Make sure the following line is in wp-config.php and it is ABOVE the “require_once(ABSPATH.’wp-settings.php’);” line: define( 'WP_CACHE', true ); Try the Settings->WP Super Cache page again and enable cache. Look in wp-content/cache/supercache/. Are there directories and files there? Anything in your php error_log? If your browser keeps asking you to save the file after the super cache is installed you must disable Super Cache compression. Go to the Settings->WP Super Cache page and disable it there. File locking errors such as “failed to acquire key 0x152b: Permission denied in…” or “Page not cached by WP Super Cache. Could not get mutex lock.” are a sign that you may have to use file locking. Edit wp-content/wp-cache-config.php and uncomment “$use_flock = true” or set $sem_id to a different value. You can also disable file locking from the Admin screen as a last resort. Make sure cache/wp_cache_mutex.lock is writable by the web server if using coarse file locking. The cache folder cannot be put on an NFS or Samba or NAS share. It has to be on a local disk. File locking and deleting expired files will not work properly unless the cache folder is on the local machine. Garbage collection of old cache files won’t work if WordPress can’t find wp-cron.php. Check your access_logs for wp-cron.php entries and that your hostname resolves to the external IP address other servers on the network/Internet use. If old pages are being served to your visitors via the supercache, you may be missing Apache modules (or their equivalents if you don’t use Apache). 3 modules are required: mod_mime, mod_headers and mod_expires. The last two are especially important for making sure browsers load new versions of existing pages on your site. The error message, “WP Super Cache is installed but broken. The path to wp-cache-phase1.php in wp-content/advanced-cache.php must be fixed!” appears at the end of every page. Open the file wp-content/advanced-cache.php in your favourite editor. Is the path to wp-cache-phase1.php correct? This file will normally be in wp-content/plugins/wp-super-cache/. If it is not correct the caching engine will not load. Caching doesn’t work. The timestamp on my blog keeps changing when I reload. Check that the path in your .htaccess rules matches where the supercache directory is. You may have to hardcode it. Try disabling supercache mode. If supercache cache files are generated but not served, check the permissions on all your wp-content/cache/supercache folders (and each of wp-content cache and supercache folders) and wp-content/cache/.htaccess. If your PHP runs as a different user to Apache and permissions are strict Apache may not be able to read the PHP generated cache files. To fix you must add the following line to your wp-config.php (Add it above the WP_CACHE define.) Then clear your cache. umask( 0022 ); If you see garbage in your browser after enabling compression in the plugin, compression may already be enabled in your web server. In Apache you must disable mod_deflate, or in PHP zlib compression may be enabled. You can disable that in three ways. If you have root access, edit your php.ini and find the zlib.output_compression setting and make sure it’s “Off” or add this line to your .htaccess: php_flag zlib.output_compression off If that doesn’t work, add this line to your wp-config.php: ini_set('zlib.output_compression', 0); After uninstalling, your permalinks may break if you remove the WordPress mod_rewrite rules too. Regenerate those rules by visiting the Settings->Permalink page and saving that form again. If your blog refuses to load make sure your wp-config.php is correct. Are you missing an opening or closing PHP tag? Your front page is ok but posts and pages give a 404? Go to Settings->permalinks and click “Save” once you’ve selected a custom permalink structure. You may need to manually update your .htaccess file. If certain characters do not appear correctly on your website your server may not be configured correctly. You need to tell visitors what character set is used. Go to Settings->Reading and copy the ‘Encoding for pages and feeds’ value. Edit the .htaccess file with all your Supercache and WordPress rewrite rules and add this at the top, replacing CHARSET with the copied value. (for example, ‘UTF-8’) AddDefaultCharset CHARSET The error message, “WP Super Cache is installed but broken. The constant WPCACHEHOME must be set in the file wp-config.php and point at the WP Super Cache plugin directory.” appears at the end of every page. You can delete wp-content/advanced-cache.php and reload the plugin settings page or edit wp-config.php and look for WPCACHEHOME and make sure it points at the wp-super-cache folder. This will normally be wp-content/plugins/wp-super-cache/ but you’ll likely need the full path to that file (so it’s easier to let the settings page fix it). If it is not correct the caching engine will not load. If your server is running into trouble because of the number of semaphores used by the plugin it’s because your users are using file locking which is not recommended (but is needed by a small number of users). You can globally disable file locking by defining the constant WPSC_DISABLE_LOCKING, or defining the constant WPSC_REMOVE_SEMAPHORE so that sem_remove() is called after every page is cached but that seems to cause problems for other processes requesting the same semaphore. Best to disable it. Set the variable $htaccess_path in wp-config.php or wp-cache-config.php to the path of your global .htaccess if the plugin is looking for that file in the wrong directory. This might happen if you have WordPress installed in an unusual way.