Hummingbird Performance – Cache & Page Speed Optimization for Core Web Vitals | Critical CSS | Minify CSS | Defer CSS Javascript | CDN vs Proxy Cache Purge

Hummingbird makes your website faster and optimizes site performance by adding new ways to boost Google PageSpeed Insights with fine-tuned controls over file compression, deferring CSS and JavaScript styles and scripts, minify for CSS and JS, Lazy Load integration, and world-class caching. Hummingbird is brought to you by the WordPress speed specialists that created Smush image optimization, now active on more than +1 million websites. Get the complete speed boost with Hummingbird and Smush. Enjoy top-tier performance and PageSpeed optimization from the start with Hummingbird Pro. Level up immediately with exclusive Pro features like Delay JavaScript Execution, Critical CSS Generation, Brotli file compression, and 119-point global asset CDN with unlimited bandwidth. Learn more about Pro. If PageSpeed Insights is making these speed recommendations Hummingbird can help: Enable text compression – Use gzip to make your site fly (Brotli Compression via CDN included with Pro). Preconnect to required origins – Use Hummingbird to establish earlier connections. Preload key requests – Prioritize resources based on order. Avoid enormous network payloads – Consider Lazy Load for comments or breaking up smaller posts. Use efficient cache – The Hummingbird Cache suite offers effective browser cache for caching any site. Fix your JavaScript execution time – Deliver smaller JS payloads, preload JS, and defer JS. Minify CSS – Strip unused code from your CSS. Minify JavaScript – Speed up the time it takes to parse your JS files. Eliminate render-blocking resources – Move critical CSS and JS inline and defer all non-critical JS/CSS. Delay JavaScript execution (Pro only) – Increase performance by delaying the loading of non-critical JS files and scripts until user interaction. Automatically generate Critical CSS (Pro only) – Substantially boost page speed and UX by prioritizing above-the-fold content. Defer unused CSS – Defer the loading of CSS not used for above-the-fold content. Lazy Load offscreen images (Smush free integration). Hummingbird scans your site and provides one-click fixes to speed up WordPress in a flash. You’ll get faster loading pages, higher search rankings (SERP) and PageSpeed scores, and happier visitors with Hummingbird’s WordPress speed optimization. Optimizing the speed of your site has never been easier! Features Available in Hummingbird Include: Scan and Fix – Get a scan of your site, find out what’s slowing it down, and use one-click performance improvements to make critical speed improvements. World-class caching – A full caching suite to load pages faster with full-page, Gravatar, and browser cache tool. Performance Reports – Pro tips for running your site at super speed. Asset Optimization – Combine, compress and position Javascript, CSS, and Google Font files for top performance. Safe Mode — Test Hummingbird settings without affecting your visitors’ experience, only logged-in admins see the optimized version. Better Rankings – Improve scores on Google PageSpeed Insights (SEO ranking factor), YSlow, Pingdom, and GTmetrix. Increase Your Conversion Rate – Don’t keep visitors waiting: faster sites convert better. GZIP Compression – Blazing-fast HTML, JavaScript, and stylesheet (CSS) transfer. Configs – Set your preferred performance settings, save them as config, and instantly upload to any other site. Font Optimization – Improve site speed, Core Web Vitals, and visual stability by preloading critical fonts and enabling fallbacks. Uptime Monitoring & Alerts – Get instant notifications if your site ever goes down. Scheduled Performance Reports – Stay on top of site speed with regular insights. Learn The Ropes With These Hands-On Hummingbird Tutorials How To Optimize WordPress For Speed With Hummingbird How To Optimize Elementor for Free Using Smush and Hummingbird How To Optimize WPBakery Sites Using Smush And Hummingbird Speed Up and Optimize Avada for Free Using Smush and Hummingbird Optimize Divi for Free Using Smush and Hummingbird Hummingbird Features to Speed Up WordPress Scan and One-Click Fix Hummingbird is a WordPress speed optimization plugin. It will scan your site, find files that are slowing it down, and provide tips and fixes for making your site run at top speed. Hummingbird even has one-click improvements like a full cache suite, one-click minify for styles and scripts, and deferring CSS and JS for quickly optimizing performance. What could be easier! World-Class Caching You’ll get a world-class caching suite, including full-page, browser, and Gravatar cache. Make your site load even faster with Hummingbird’s complete set of cache tools that give your visitors a faster browsing experience. Including full-page, browser and Gravatar caching. Asset Optimization Did you know that loading too many files in your site’s header can slow it down? Hummingbird now gives you granular control with separate Combine and Compress optimization modes, so you can fine tune your Asset Optimization like a pro. Reorder, defer, compress and exclude CSS and JavaScript files with one-click. Transfer Data at Top Speed With GZIP Hummingbird has GZIP powers to make sharing your site more efficient. Sending zipped files is faster and can save you money on hosting. And don’t worry about setup, send Hummingbird instructions with the click of a button and she’ll handle the rest. Built-in Cloudflare Integration Hummingbird can be used to control your Cloudflare browser cache and Automatic Platform Optimizations (APO) settings as well! Simply add your Cloudflare API key and configure away. Font Optimization Boost site speed, Core Web Vitals, and the visual stability of pages for users with Hummingbird’s one-click font optimization features: Preload Fonts, which instructs browsers to preload essential fonts, and Swap Web Fonts, which applies a temporary fallback font until the primary one loads. Fully Compatible With Smush Image Optimization You can complement Hummingbird’s WordPress speed optimization features with our award-winning sister-plugin Smush image optimization. Smush compresses your images, giving your site less to load – and thus a faster load time. Hummingbird + Smush integrate perfectly together, and are the perfect match to speed up WordPress. Compress, optimize (optimise), and fix PageSpeed performance with properly sized images, lazy load, next-gen WebP convert, image formatting, and more. Save time with Hummingbird Configs Configs allow you to save your preferred Hummingbird configuration settings and apply them to your other sites in a few clicks. You can create unlimited configs. Delay Javascript Resources (Pro Only) Boost site performance dramatically by delaying the loading of JS files and third-party scripts until direct user interaction (e.g. scroll or click). Enjoy faster loading pages, improve web vitals, and ace your PageSpeed scores. Activate in one click, includes user interaction timeout and the option to exclude critical files from being delayed. A paid WPMU DEV account (the developers of Hummingbird) is required to access this feature. You can check out our affordable plans here. Generate Critical CSS (Pro Only) Maximize site speed and user experience by prioritizing only the CSS that matters most. The Generate Critical CSS feature intelligently generates and embeds critical CSS in the head of each page, giving priority to above-the-fold content and significantly improving loading speed. Updates to your critical CSS are automated with every site design change, and you can enable/disable with a click. Faster Websites Rank Higher, Convert Better Every millisecond counts: your visitors expect an ever-faster website, with a page load time of under two seconds expected – and the norm. If visitors don’t get that on your site, they will leave. If you’re running a business website or eCommerce store, that means if your website does not load quickly, you will lose sales. Hummingbird is here to help you; it’s a one of a kind WordPress performance optimization plugin that can make your site run at superspeed, for free! You get our WordPress performance optimization suite, which includes minification and GZIP for small page sizes, full caching for faster loading, and integration with Cloudflare’s APO / browser cache, and our sister-plugin Smush image optimization. Hummingbird is built with ease-of-use in mind; it makes your WordPress site faster, but it’s also fast to set up. You can scan your site and implement recommended changes in one-click, getting a fast site in mere minutes. All the above is free and will speed up WordPress for you. If you need the very fastest WordPress site, you should get a WPMU DEV Membership. Our Membership gives you access to Hummingbird Pro – which features automated scanning, enhanced minify compression (with 2x the regular optimization), CDN hosted minification – alongside Smush Pro image optimization, all our premium WordPress plugins, and 24/7 WordPress support. It’s an incredible deal, and you can find out more here. What do People say About Hummingbird? ★★★★★ “Hummingbird is so easy to use. I thought it wouldn’t change my speed much because I already made improvements. I ran the scan, it gave me recommendations, I pushed a button to apply them and it made my site even faster!” – Camilo ★★★★★ “Hummingbird is getting smarter with each update. Today it’s become so good that it forced me to remove giant cache and optimization plugins like WP Super Cache and WP Sweep because now Hummingbird includes all those features – but in a more impressive way.” – swagatam1975 ★★★★★ “Hummingbird took me from 32 to 84 on Google page speed plus made my site 50% faster on GTmetrix!” – Nicolas ★★★★★ “I just built a real bloated sack of crap of a WP site, and after configuring Hummingbird and letting it do its thing, the site is actually fast — much faster than it has any right to be…I’m impressed.” – Cacarr A Note From Hummingbird Hey! This is Hummingbird, your trusted solution to speed up WordPress. I’m part of the WPMU DEV team, a superhero-suite of WordPress plugins, services, and support. Here are some of our other free plugins: Smush – Image Compression and Optimization Forminator – Form, Quiz, Poll and Survey Builder Hustle – Pop-ups, Slide-ins and Email Opt-ins And if you need ALL our Pro plugins AND 24/7 WordPress support, get WPMU DEV membership! My superhero friends run the WPMU DEV Blog, your source for the very best WordPress tutorials. If you need to be in the know about WordPress, check it out. Thanks for looking at Hummingbird, and I look forward to flying through your site to make it faster than ever. Enjoy, The Hummingbird About Us WPMU DEV is a premium supplier of quality WordPress plugins, services and support. Join us here: https://wpmudev.com/ Don’t forget to stay up to date on everything WordPress from the Internet’s number one resource: WPMU DEV Blog Hey, one more thing… we hope you enjoy our free offerings as much as we’ve loved making them for you!

This plugin does not install nor configure a cache proxy. It acts as an interface with such services. One common method of caching content for websites is via the use of reverse proxy caching. Common examples of this are Varnish and NGINX. These systems allow a website to update content and have the visitor’s experience cached without the need for complex plugins storing the files locally and using up a user’s disk space. A reverse proxy cache is installed in front of a server and reviews requests. If the page being requested is already cached, it delivers the cached content. Otherwise it generates the page and the cache on demand. The Proxy Cache Purge plugin sends a request to delete (aka flush) the cached data of a page or post every time it’s modified. How It Works When content on a site is updated by WordPress, the plugin reaches out to the proxy cache service with the URL of the page, requesting the cache be deleted. Not all pages are deleted from the cache on every change. For example, when a post, page, or custom post type is edited, or a new comment is added, only the following pages will purge: The front page The post/page edited Any categories, tags, and/or custom taxonomies associated with the page Related feeds Associated JSON API pages In addition, your entire cache will be deleted on the following actions: Changing themes Pressing the Empty Cache button on the toolbar Plugins can hook into the purge actions as well, to filter their own events to trigger a purge. On a multisite network using subfolders, only network admins can purge the main site. Keep Your Cache Warm Purging is only half the story. Once Proxy Cache Purge empties a page, the cache for that URL is gone, so the next visitor triggers a full uncached render and waits for it. On busy sites this “cache stampede” shows up as slow pages right after every update. Cacheability Pro is a companion plugin that closes that gap: it automatically re-warms purged URLs in the background so visitors keep hitting fast, cached responses, and it tunes your cache headers so more of your pages stay cacheable in the first place. Proxy Cache Purge handles invalidation; Cacheability Pro handles everything around it. Monitor Your Cache Proxy Cache Purge keeps your cache fresh, but how often is it actually being hit? If you run your own Varnish or NGINX server, GetPageSpeed Amplify shows your cache hit rate, request volume, and backend health over time, with a free tier. Proxy Cache Purge handles invalidation; Amplify shows you whether the cache is doing its job. Development Mode If you’re working on a site and need to turn off caching in one of two ways: Add define( 'VHP_DEVMODE', true ); to your wp-config.php file Go to Proxy Cache -> Settings and enable Debug Mode for 24 hours at a time That will break cache on page loads. It is not recommended for production! Cache Tags (BETA) As of version 5.4.0, Proxy Cache Purge includes an optional Cache Tags / Surrogate Keys purge mode. This feature is marked as BETA and is disabled by default. When enabled, the plugin: Adds cache-tag headers to WordPress responses (for example, tagging pages by post ID, post type, taxonomy terms, author, and archives). Uses tag-based purges instead of individual URL purges when content is updated, which can reduce purge traffic and improve consistency on complex sites. Requirements: A proxy cache that supports Cache Tags / Surrogate Keys and advertises this via standard Surrogate-Capability headers (for example, Surrogate-Capability: vhp="Surrogate/1.0 tags/1"). How to enable: Go to Proxy Cache → Settings → Purge Method and check “Use Cache Tags (Surrogate Keys)”. The checkbox is only enabled when your cache tells WordPress it supports tags (or when you explicitly enable it via a define). Alternatively, you can force-enable or force-disable detection via wp-config.php: define( ‘VHP_VARNISH_TAGS’, true ); // Force treat cache as tag-capable define( ‘VHP_VARNISH_TAGS’, false ); // Force treat cache as not tag-capable Because this feature depends on your cache configuration, it is recommended that you test it carefully in staging before enabling it on production. Background Purging with WP-Cron On busy sites, sending many PURGE requests directly from admin requests can slow things down. When you define DISABLE_WP_CRON as true in wp-config.php (because you are running a real system cron that calls wp-cron.php), Proxy Cache Purge automatically switches to an asynchronous mode: Purge requests (both URL-based and tag-based, when Cache Tags are enabled) are collected into a small per-site queue. The queue is processed by WP-Cron in the background, keeping your admin and content-editing actions responsive even when many URLs or tags must be invalidated. Object-cache purges (the “Purge Database Cache” option) remain synchronous and are not affected by this behaviour. The Proxy Cache settings page and Site Health integration expose basic queue status so you can verify that background purging is healthy; if the queue appears large or very old, check that your system cron is correctly invoking WordPress cron. Important: Cron Frequency and Cache Freshness When using background purging, the frequency of your system cron determines how quickly cache invalidations are processed. The longer the interval between cron runs, the longer visitors may see stale content after updates. For minimal stale content, run your system cron every minute: * * * * * /usr/bin/php /var/www/html/wp-cron.php If you can tolerate slightly longer delays, every 2-5 minutes is also acceptable. However, running cron less frequently (e.g., every 15 minutes) means cache purges may be delayed by that amount after content changes. Note: Scheduled posts are handled specially. When a scheduled post is published via WP-Cron, the cache is purged synchronously within the same cron run, ensuring immediate cache invalidation without waiting for the next cron execution. For detailed instructions on setting up a proper Linux-based WordPress cron, see: WordPress Cron Optimization. Disabling Background Purging If you have DISABLE_WP_CRON defined but do not want background purging (for example, on low-traffic sites where immediate purges are preferred), you can force-disable cron-based purging by adding this to your wp-config.php: define( 'VHP_DISABLE_CRON_PURGING', true ); With this constant set, all cache purges will execute immediately during the request, regardless of the DISABLE_WP_CRON setting. WP-CLI Purge Purge commands let you empty the cache. wp varnish purge – Flush the entire site cache (equivalent to clicking “Empty Cache” in admin) wp varnish purge --all – Explicitly flush the entire site cache wp varnish purge – Flush cache for a specific URL and all content below it (wildcard) wp varnish purge --url-only – Flush cache for only the exact URL specified (no wildcard) wp varnish purge --tag= – Flush cache by tag (requires Cache Tags mode to be enabled) Examples: wp varnish purge – Purge entire site wp varnish purge --all – Same as above, more explicit wp varnish purge https://example.com/hello-world/ – Purge this URL and everything below it wp varnish purge https://example.com/hello-world/ --url-only – Purge only this exact URL wp varnish purge https://example.com/wp-content/themes/ --wildcard – Purge all theme files wp varnish purge --tag=p-123 – Purge all pages tagged with post ID 123 wp varnish purge --tag=pt-post – Purge all cached pages of post type “post” Debug Debugging can help you figure out why your cache isn’t working as well as it could. The default is for your home page, but you can pass any URL on your domain. wp varnish debug [ ] Available parameters: [--include-headers] — Include headers in debug check output [--include-grep] — Grep active theme and plugin directories for common issues DevMode Development mode allows you to disable the cache, temporarily. wp varnish devmode [ ] – Change development mode state Async purge queue (cron-mode) When you define DISABLE_WP_CRON as true and run a real system cron for WordPress, Proxy Cache Purge can move heavy purge work into a small background queue that is processed by WP‑Cron. You can inspect and manage that queue via WP‑CLI: wp varnish queue status – show whether cron-mode is active, if a full purge is queued, counts of queued URLs/tags, and the last queue run time. wp varnish queue process – process any items currently in the queue (useful to run after deploys or cache‑sensitive operations). wp varnish queue clear – clear the queue without sending any PURGE requests. These commands do not replace your normal WordPress cron (you still need a cron entry that calls wp cron event run --due-now or hits wp-cron.php), but they give you a simple operational handle when using cron‑mode. Understanding Purge Behavior There are different types of cache purges, and they behave differently: Manual Purges (Admin Bar) “Purge Cache (All Pages)” – Sends a single regex purge request to invalidate the entire cache. Always executes immediately. “Purge Cache (this page)” – Purges only the exact URL you’re viewing. Always executes immediately. Manual purges are always immediate, even when background cron-mode is enabled. This is intentional: when you click a button, you expect immediate results. Automatic Purges (Post Save/Update) When you save or update a post, the plugin automatically purges: The post’s URL The homepage Category archive pages Tag archive pages Author archive page Date-based archives RSS feeds Related REST API endpoints This can be 20-50+ URLs depending on your site structure. When cron-mode is enabled, these automatic purges are queued and processed in the background to avoid slowing down the post editor. Key Difference Action URLs Purged Uses Cron Queue? “Purge Cache (All Pages)” 1 (regex) No – always immediate “Purge Cache (this page)” 1 No – always immediate Post save/update 20-50+ Yes (if cron-mode enabled) If you need to immediately purge all URLs related to a specific post (not just the post URL), save the post – the automatic purge will handle all related URLs.