Measure the real problem first
You cannot fix what you have not measured, and 'it feels slow' is not a diagnosis. Open PageSpeed Insights (pagespeed.web.dev), enter your URL, and read two things: the Core Web Vitals and the lab metrics. Focus on the mobile tab, since most visitors are on phones. Then measure TTFB (Time To First Byte) — how long your server takes to send the first byte — because it separates a server problem from a delivery problem.
Healthy targets are LCP under 2.5 seconds, INP under 200 ms, CLS under 0.1, and TTFB under about 200 ms. If TTFB is high, the bottleneck is on the server side: hosting, PHP or the database. If TTFB is fine but LCP is high, the bottleneck is the page itself — usually large images and how far they travel to the visitor. This one measurement tells you which fixes below to start with.
The real causes of a slow site
Most slow sites share a handful of causes. A slow server or crowded shared hosting drives up TTFB before a single image loads. Heavy pages come next — oversized images (usually the largest thing on a page), bloated themes and page builders that ship dozens of stylesheets and scripts. Too many third-party scripts (chat widgets, heatmaps, trackers, extra fonts) each add a request and block rendering.
Render-blocking CSS and JavaScript delay the first paint even when the server is fast. And distance matters: a single server far from many of your visitors adds latency to everything, and a traffic spike can overwhelm it. Almost every slow site is some mix of these — repeated server work, heavy assets, blocking scripts and physical distance.
Understanding Core Web Vitals
Google ranks partly on Core Web Vitals, so it helps to know what each one measures. LCP (Largest Contentful Paint) is how long the main content — often the hero image — takes to appear; it is hurt most by slow servers and heavy, distant images. INP (Interaction to Next Paint) is how quickly the page responds when a visitor taps or clicks; it is hurt by heavy JavaScript blocking the main thread.
CLS (Cumulative Layout Shift) is how much the layout jumps around while loading; it is hurt by images and ads without reserved space and by late-loading fonts. Fixing the causes above — faster delivery, lighter images, less JavaScript and reserved space for media — is exactly what improves these three numbers.
The fixes that move the numbers
Work in order of impact. Cache: serve a ready-made page instead of rebuilding it every visit — the biggest single win for TTFB and server load. Images: resize them to the size they are shown and serve modern formats (WebP/AVIF), which usually dominate page weight. Scripts: remove third-party scripts you do not need and defer the rest so they stop blocking the first paint.
Reserve space for images and ads so the layout does not jump (better CLS), and load fonts without blocking rendering. Then shorten the distance your content travels with a CDN. Each fix targets a specific cause, and together they move LCP, INP and CLS at once.
A CDN solves the distance and spike problem
Even after tuning your server and pages, one server can only be in one place. A CDN copies your static files to edge servers around the world, so every visitor is served from the nearest one — lower latency and a lower LCP for people far from your origin, plus resilience when traffic spikes because the edge absorbs the load. Modern delivery (Brotli compression, HTTP/2) and automatic SSL, WAF and DDoS protection come along with it.
cdn.com.tr does this without a rebuild: route your domain through the CDN and the edge starts caching and delivering your assets from a location close to each visitor. Dynamic pages keep working normally, certificates renew themselves, and the distance that was hurting your LCP disappears.
Where speed matters most
Readers leave slow articles; faster pages and edge caching keep them reading and help a popular post survive a traffic spike.
Every extra second on a product or checkout page lowers conversions; caching and a CDN keep a busy store responsive.
First impressions and ad quality scores depend on speed; a fast, close-to-the-visitor page lifts both.
Site speed FAQ
What are Core Web Vitals?
Three metrics Google uses to score real-world experience: LCP (how fast the main content appears), INP (how fast the page responds to input) and CLS (how stable the layout is). Improving them helps both users and rankings.
How do I lower a high TTFB?
A high TTFB is a server-side problem: use up-to-date PHP, add page caching so pages are not rebuilt every visit, add a Redis object cache for query-heavy sites, and choose faster hosting. A CDN then serves cached responses even closer to visitors.
Will a CDN alone make my site fast?
A CDN removes the distance problem and absorbs spikes, which is a big part of speed. But if a high TTFB comes from the server, or images are oversized, fix those too — a CDN delivers your pages faster, it does not rebuild a slow origin for you.
Why is my site slower on mobile?
Phones have weaker CPUs and often slower networks, so heavy JavaScript and large images hurt more. Lighter images, less script and cached, close-by delivery are what move the mobile scores Google ranks on.