Speed, Cache & CDN articles

Speed, Cache & CDN 219 How to monitor your site performance in cPanel cPanel keeps a record of everything that happens on your hosting - who visited, how much traffic you used, which...
Speed, Cache & CDN 201 The site is slow: what actually makes a difference «The site is slow» means different things depending on who says it: the first page takes ages to appear, the admin...
Speed, Cache & CDN 238 Cloudflare: when it helps, how to switch it on, and the cache that fools you Cloudflare sits in front of your site: visitors reach it first, and it comes to us for what it needs. That brings...
Speed, Cache & CDN 189 The site is slow: what to measure before you change plan «The site is slow, I think I need a bigger plan.» It is one of the messages we get most, and most of the time the...
Speed, Cache & CDN 227 What a CDN is, and when it makes a difference (and when it does not) A CDN (content delivery network) is a set of machines spread around the world that keep copies of your site and hand...
Speed, Cache & CDN 201 What a CDN does for you: caching, compression, images and protection People switch a CDN on expecting speed and get four different things at once. It is worth knowing which is which,...
Speed, Cache & CDN 199 Putting a CDN in front of your site, step by step Putting a CDN in front of your site means changing who answers for the domain DNS. It is a ten-minute change that,...
Speed, Cache & CDN 226 Switching the CDN off, and confirming it really is off There are three ways to switch a CDN off, and they are very different from one another. Picking the wrong one gets...
Speed, Cache & CDN 217 Cloudflare: what it is, what changes, and what stays the same Cloudflare is a company that puts its network in front of your site: visitors reach it first, and it comes to us for...
Speed, Cache & CDN 198 Putting a domain on Cloudflare This is the route from start to finish on the Cloudflare side: create the account, add the domain, check what it...
Speed, Cache & CDN 204 Creating a subdomain on Cloudflare With the domain on Cloudflare, creating a subdomain becomes a job of two halves, in two different panels. Doing only...
Speed, Cache & CDN 204 Switching on SSL at Cloudflare without breaking the site This is the single most important setting Cloudflare has, and the easiest one to get wrong. The wrong value does not...
Speed, Cache & CDN 216 Taking the whole DNS zone to Cloudflare without losing records When you add a domain to Cloudflare, it reads your current DNS and brings across what it finds. That gives the...
Speed, Cache & CDN 174 Cache rules for a WordPress site, without hiding the dashboard Switching Cloudflare on and touching nothing else caches your images, stylesheets and scripts. The pages are still...
Speed, Cache & CDN 217 The Cloudflare options worth having, and the ones that cause trouble The Cloudflare dashboard holds dozens of switches, all with names promising speed or safety. Some are worth having:...
Speed, Cache & CDN 175 What eats CPU on a website, and how to bring it down The processor is the one resource in your account that does not fail when it runs out: it slows down. No error...
Speed, Cache & CDN 185 Compression: confirming it is on, and measuring what you gained Compression shrinks pages before they travel, and the browser unpacks them at the other end. Because HTML, CSS and...
Speed, Cache & CDN 207 Measuring your site speed: which tools, and what the numbers mean Everybody has run a speed test on their own site, seen a coloured score, and been none the wiser. The problem is not...
Speed, Cache & CDN 176 admin-ajax eating your resources: how to find out and cut it down admin-ajax.php is the door through which plugins talk to the server in the background, without reloading the page....
Speed, Cache & CDN 139 Installing and tuning a page cache Without a cache, every visit makes the server build the page again: query the database, run the PHP, assemble the...
Speed, Cache & CDN 214 Clearing the cache: the browser’s, the computer’s, and the site’s “Clear your cache” is the most given and least useful advice, because there is no such thing as the cache. There are...
Speed, Cache & CDN 95 LiteSpeed Cache for WordPress: the first settings The server your site runs on uses LiteSpeed Enterprise, and the LiteSpeed Cache plugin is the piece of WordPress...
Speed, Cache & CDN 87 Image optimisation and WebP Images are often the heaviest part of a page. WebP is an image format made by Google that usually keeps the same...
Speed, Cache & CDN 82 Core Web Vitals in plain words Core Web Vitals are three measurements Google uses to describe how a page feels to the person visiting it: whether...
Speed, Cache & CDN 99 Browser caching with .htaccess Browser caching is the kind that lives on the visitor’s own computer: if the logo, the CSS and the JavaScript arrive...
Speed, Cache & CDN 76 Hotlink protection: stop others using your bandwidth Hotlinking is when another website displays an image of yours straight from your server, instead of keeping a copy...
Speed, Cache & CDN 76 Fast for you, slow for everyone else: why You open your site and it appears in a blink. A customer says it drags. You are both right, because you are not...
Speed, Cache & CDN 79 How to fix a slow LCP, the Largest Contentful Paint LCP measures how long the largest visible element takes to appear when the page opens, nearly always the image at...
Speed, Cache & CDN 85 How to fix CLS: why the page jumps while it loads CLS measures how much the content moves while the page loads: you go to tap a button and at the last instant an ad...
Speed, Cache & CDN 78 How to fix a poor INP: the page appears but reacts slowly INP measures how long the page takes to react to a tap or a click, from the moment you press to the moment something...
Speed, Cache & CDN 73 AVIF or WebP: which image format to use, and what to do for old browsers For most sites, WebP is enough and it is the easier one. AVIF often gives even smaller files on photographs, but it...
Speed, Cache & CDN 94 Lazy loading images and videos: what to defer and what never to Lazy loading makes the browser request an image or a video only when it is about to appear on screen, instead of...
Speed, Cache & CDN 76 Minifying CSS and JavaScript without breaking the site Minifying means taking the spaces, line breaks and comments out of a CSS or JavaScript file so it weighs less. A...
Speed, Cache & CDN 103 HTTP/2 and HTTP/3: how to see which one your site uses, and whether it matters HTTP/2 and HTTP/3 are two newer versions of the “conversation” between the browser and the server. Our web server...
Speed, Cache & CDN 83 Gzip or Brotli: which one your visitors get, and why it can differ Gzip and Brotli are two ways of compressing text (HTML, CSS, JavaScript, JSON) before it travels. Brotli usually...
Speed, Cache & CDN 84 High TTFB: how to find where the server response time goes TTFB (time to first byte) is the time from the request to the arrival of the first byte of the reply. If it is high,...
Speed, Cache & CDN 92 Visitors still see the old CSS or logo: versioned file names and cache busting You changed the CSS, the logo or a script, and you see the new one but visitors keep seeing the old version. The...
Speed, Cache & CDN 85 Web fonts slowing the page: font-display, fewer files and hosting them yourself Every typeface the site uses is a file to download, and every variant (regular, bold, italic) is another. If the...
Speed, Cache & CDN 85 PageSpeed Insights warnings explained: render-blocking, unused JavaScript and the rest The suggestion list in PageSpeed Insights looks like a to-do list. It is not. It is a menu of ideas, each with a...
Speed, Cache & CDN 80 How to read a GTmetrix report: the waterfall, the grade and what to ignore GTmetrix tests a page and hands back a grade, metrics and, above all, the waterfall: the list of everything the page...
Speed, Cache & CDN 46 A site that loads on slow mobile data: how to make it lighter The short answer: on a slow mobile connection what hurts is the weight of the page, not only the speed of the...
Speed, Cache & CDN 56 A website people can install like an app: PWA basics The short answer: a PWA is a normal website with two things added: a small file that describes it (the manifest)...
Speed, Cache & CDN 63 Faster first paint: preload, preconnect and render-blocking CSS The short answer: before showing the page, the browser has to download the CSS and discover which images and fonts...
Speed, Cache & CDN 54 Object cache with Redis for WordPress on a VPS: what it speeds up and how to set it up The short answer: an object cache keeps in memory the answers WordPress asks the database for, so it does not ask...
Speed, Cache & CDN 58 Videos on your website: upload them or embed from a video service The short answer: for most sites, embed the video from a proper video service (such as YouTube or Vimeo) instead of...
Speed, Cache & CDN 53 Load testing your site before a launch: how to do it without causing the outage The short answer: a load test simulates many visitors at once to see whether the site copes and where it gives way...
Speed, Cache & CDN 55 Orange cloud or grey cloud at Cloudflare: which records to proxy and which to leave DNS only The short answer: every record in Cloudflare’s DNS has a cloud beside it. Orange (Proxied) means visitors talk to...
Speed, Cache & CDN 64 The real visitor IP behind Cloudflare: logs, applications and IP blocks For whoever runs the site, codes in it or has a VPS. With the site orange on Cloudflare, what connects to the server...
Speed, Cache & CDN 60 Cloudflare blocked a real customer: security events, error 1020 and narrow exceptions The short answer: when a customer says they cannot log in, pay or send a form, and the site is orange on Cloudflare,...
Speed, Cache & CDN 61 AutoSSL behind Cloudflare: why the free certificate leaves names out or fails to renew The short answer: the server’s free certificate (cPanel’s AutoSSL) is still needed with Cloudflare in front: it...
Speed, Cache & CDN 50 Is this page coming from the Cloudflare cache? Reading cf-cache-status and purging one address The short answer: every response that goes through Cloudflare carries a header, cf-cache-status, that says whether...
Speed, Cache & CDN 48 Cache headers explained: Cache-Control, Expires, ETag and how a CDN reads them The short answer: every file the server sends comes with a few lines the visitor never sees, the headers. Some of...
Speed, Cache & CDN 48 Origin and edge in a CDN: HIT, MISS, BYPASS and what an origin shield does The short answer: a CDN has two sides. The origin is your hosting server, where the site lives. The edge servers are...
Speed, Cache & CDN 42 Purging a CDN cache: one file, a folder or everything, and when not to purge The short answer: purging tells the CDN to throw away the copies it holds, so the next request goes to the origin...
Speed, Cache & CDN 37 A CDN in front of a shop or members area: what must never be cached The short answer: in a shop, or on any site with accounts, the same page is not the same for everyone: the cart, the...
Speed, Cache & CDN 39 A CDN only for images, video and downloads, or for the whole site: how to choose The short answer: there are two ways to put a CDN to work. The whole site: the domain points at the CDN (through its...