SQLite Object Cache vs PlugoSpeed

PlugoSpeed is a WordPress performance plugin that combines page caching, asset optimization, and Core Web Vitals improvements in a single lightweight package. It generates static HTML cache files served directly from disk via Apache — bypassing PHP and WordPress on cached requests. In testing on a standard VPS, this approach achieves sub-50ms TTFB and PageSpeed scores of 95/100 on desktop. A React 18 dashboard provides real-time cache hit rates, bandwidth saved, and PageSpeed score tracking — no jQuery required. Core Features (Free) Static HTML Cache Pages are stored as static .html files on disk. Apache serves them directly — no PHP, no database, no WordPress bootstrap. Cache TTL is configurable (default: 24 hours). HTML Minification Removes unnecessary whitespace and comments from the final HTML output, reducing page size without affecting content or functionality. CSS Minification Minifies stylesheet files inline, reducing transfer size. Combine is intentionally disabled by default for HTTP/2 compatibility. JavaScript Defer Adds defer to non-critical scripts, improving Time to Interactive (TTI) and Largest Contentful Paint (LCP) scores on mobile. Image Lazy Loading Adds native loading="lazy" to images and iframes below the fold. Injects explicit width and height attributes to reduce Cumulative Layout Shift (CLS). Database Cleanup Scheduled cleanup of post revisions, auto-drafts, spam comments, and expired transients. Configurable schedule: daily, weekly, or monthly. Cache Preloading After purge, PlugoSpeed re-warms the cache automatically by walking your XML sitemap. Rate-limited to avoid server overload. Auto Cache Purge Cache is invalidated on post save, theme change, plugin activation, and WooCommerce stock/price updates. PageSpeed Dashboard Tracks your Google PageSpeed Insights score over time with a 30-day graph. Shows live cache hit/miss ratio, bandwidth saved, and page count. Pro Features Remove Unused CSS (RUCSS) Generates a per-page stylesheet containing only the CSS rules that are actually used. Eliminates render-blocking CSS from page builders and plugin stylesheets. Requires a PlugoPress API key. Critical CSS Inlines the above-the-fold CSS directly in , eliminating render-blocking for a faster LCP. Requires a PlugoPress API key. WebP Image Serving Automatically serves .webp versions of images to supported browsers, reducing image payload by 25–35% without quality loss. Upgrade to Pro → plugopress.com/plugospeed/ Compatibility PlugoSpeed is tested and verified compatible with: Page Builders: Elementor, Divi, Beaver Builder, Bricks, Oxygen, WPBakery Themes: Astra, GeneratePress, Kadence, Hello Elementor, OceanWP, Blocksy, Neve, Flatsome E-Commerce: WooCommerce (cart exclusion, stock purge, vary by currency) Multilingual: WPML, Polylang (vary cache by language) SEO: Rank Math, Yoast SEO, All in One SEO CDN: Cloudflare (Pro: API purge integration) Technical Highlights Apache .htaccess rules serve cached HTML at low TTFB — before PHP loads advanced-cache.php drop-in captures misses and writes cache files Optimizer pipeline: Image → JS → CSS → HTML (order matters for correctness) WooCommerce cart/checkout pages are automatically excluded from cache Logged-in users never receive cached pages (preserves nonces and personalisation) Action Scheduler handles background jobs (preload, cleanup, RUCSS generation) REST API powers the dashboard — all actions are nonce-protected with manage_options capability checks Links Plugin Page Documentation Changelog Support External Services This plugin connects to the following external services: Google PageSpeed Insights API Purpose: Measures your site’s performance score and Core Web Vitals (LCP, CLS, FID) When it is called: Only when viewing the PlugoSpeed dashboard or when a manual refresh is triggered by the site administrator Data transmitted: Your site’s public URL — no personal data is sent Terms of Service: https://developers.google.com/terms Privacy Policy: https://policies.google.com/privacy PlugoPress Cloud API (api.plugopress.com) Purpose: Powers Pro features: Remove Unused CSS (RUCSS) and Critical CSS generation When it is called: Only when a valid API key is configured by the site administrator AND the corresponding Pro feature is enabled Data transmitted: The page URL and rendered HTML of the requested page, used solely for CSS analysis Terms of Service: https://plugopress.com/terms Privacy Policy: https://plugopress.com/privacy-policy PlugoPress Badge Service (plugopress.com) Purpose: Displays a performance badge in the PlugoSpeed dashboard When it is called: When the dashboard is viewed and a PageSpeed score is available Data transmitted: Only the numeric PageSpeed score is included in the image URL — no personal data is sent Terms of Service: https://plugopress.com/terms Privacy Policy: https://plugopress.com/privacy-policy

A persistent object cache helps your site perform well. This one uses the widely available SQLite3 extension, and optionally the igbinary and APCu extensions to php. Many hosting services offer those extensions, and they are easy to install on a server you control. What is this about? It’s about making your site’s web server perform better. An object cache does that by reducing the workload on your MariaDB or MySQL database. This is not a page cache; these persistent objects go into a different kind of cache. These objects aren’t chunks of web pages ready for people to view in their browsers, they are data objects for use by the WordPress software. Caches are ubiquitous in computing, and WordPress has its own caching subsystem. Caches contain short-term copies of the results of expensive database lookups or computations, and allow software to use the copy rather than repeating the expensive operation. This plugin (like other object-caching plugins) extends WordPress’s caching subsystem to save those short-term copies from page view to page view. WordPress’s cache happens to be a memoization cache. Without a persistent object cache, every WordPress page view must use your MariaDB or MySQL database server to retrieve everything about your site. When a user requests a page, WordPress starts from scratch and loads everything it needs from your database server. Only then can it deliver content to your user. With a persistent object cache, WordPress immediately loads much of the information it needs. This lightens the load on your database server and delivers content to your users faster. Who should use this? If your site runs on a single web server machine, and that server provides the SQLite3 and igbinary extensions to php, this plugin will almost certainly make your site work faster. And if that server provides the APCu extension, this plugin uses it too. Some hosting providers offer redis cache servers. If your provider offers redis, it may be a good choice. You can use it via the Redis Object Cache plugin. Sites using redis have one SQL database and another non-SQL storage server: redis. Other hosting providers offer memcached, which has the Memcached Object Cache plugin. And some large multipurpose cache plugins, such as the LiteSpeed Cache, also offer object caching based on one of those cache server software packages. The cache-server approach to object caching comes into its own when you have multiple load-balanced web server machines handling your site. SQLite doesn’t work correctly in a multiple-web-server environment. But, for single-server site configurations, SQLite, possibly assisted by APCu, performs well. And the vast majority of sites are single-server. APCu APCu is an in-memory storage medium. It lets php programs, like WordPress, store data in shared memory so it’s very fast to retrieve when needed. If APCu is available on your host server, you can configure this plugin to use it. It reduces the typical cache lookup time to one-fifth or less of the SQLite lookup time, which is itself a few tens of microseconds. Performance counts, especially on busy web sites. Please look at Installation to learn how to configure this plugin to use APCu. The plugin works fast without it, and faster with it. WP-CLI: Even if APCu is in use, caching with SQLite is necessary when your web site uses WP-CLI, because WP-CLI programs do not have access to the APCu cache. This plugin writes all cached data both to APCu and to SQLite and makes sure the two are synchronized. WP-CLI You can control this plugin via WP-CLI once you activate it. Please type this command into your shell for details. wp help sqlite-object-cache Credits Thanks to Till Krüss. His Redis Object Cache plugin serves as a model for this one. And thanks to Ari Stathopoulos and Jonny Harris for reviewing this. Props to Matt Jones for finding and fixing a bug that appeared on a heavily loaded system. Thanks to Massimo Villa for testing help, and to nickchomey for a comprehensive code review. All defects are, of course, entirely the author’s responsibility. And thanks to Jetbrains for the use of their software development tools, especially PhpStorm. It’s hard to imagine how a plugin like this one could be developed without PhpStorm’s tools for exploring epic code bases like WordPress’s. How can I learn more about making my WordPress site more efficient? We offer several plugins to help with your site’s database efficiency. You can read about them here.