Site speed and SEO: the short answer
Site speed is a confirmed ranking factor. Since 2021, Google has measured real user experience through Core Web Vitals: loading (LCP), responsiveness (INP) and visual stability (CLS). A slow site slides down the results and loses visitors before the page even renders. The fix starts at the foundation: lightweight architecture, optimized images and a CDN.
Why Google rewards speed
Google wants to send users to pages that work fast. This is not new: speed has counted for desktop rankings since 2010 and for mobile since the 2018 Speed Update. The Page Experience update followed in 2021, and since then Google has judged your site on how real visitors experience it, not on how it performs in a lab.
One thing to know if you are reading older SEO articles: in March 2024, Google replaced the FID metric (First Input Delay) with INP (Interaction to Next Paint). FID only looked at the first interaction; INP measures the slowest responses across the whole visit. A site that used to pass on FID can still fail on INP.
These are the thresholds Google uses for a “good” rating:
2.5 s
maximum LCP: largest element on screen
200 ms
maximum INP: response to clicks and typing
0.1
maximum CLS: layout shift while loading
75%
of your visits must fall within those limits
The three Core Web Vitals explained
Largest Contentful Paint measures how quickly the biggest element above the fold becomes visible. Usually that is your hero image or headline. Target: within 2.5 seconds.
Interaction to Next Paint measures how quickly the page responds to clicks, taps and typing, across the entire visit. INP replaced FID in March 2024 and is stricter.
Cumulative Layout Shift measures whether the page jumps around while loading. A button that moves at the exact moment you click it is what this metric punishes.
Want to go deeper into the metrics and how they are measured? Read our full guide to Core Web Vitals.
Speed is a conversion factor too
Google aside: visitors do not wait. Someone arriving on mobile over 4G who stares at a white screen for three seconds is gone before your story starts. Every step of your funnel suffers, from first impression to checkout. A fast site pays off twice: better positions and more enquiries from the same traffic. For the second half of that equation, read our piece on conversion rate optimization.
How we build fast sites
We do not optimize after the fact. We start with an architecture that rules slowness out. We build static sites with Astro: the browser gets only what it needs, with no heavy JavaScript framework that has to boot first. We explain that choice in why we build with Astro.
On top of that:
- Images are optimized automatically and served in modern formats like WebP and AVIF, sized correctly per screen.
- Fonts load with
font-display: swap, so text is readable immediately and the layout does not jump. - Everything sits on a CDN at the edge of the network, close to the visitor.
- Schema markup and clean HTML are in from day one, as part of the broader technical SEO work.
Want to know where your site stands?
Test your site with PageSpeed Insights and pay attention to the field data at the top (real visitors), not just the lab score. Prefer a second opinion from us? Request a free SEO check and you will get the bottlenecks in writing.
Keeping your site fast after launch
A fast site turns slow again when nobody is watching. Every marketing pixel, chat widget and plugin adds weight. That is why speed belongs in maintenance: measure with real user data, set budgets for page weight, and question every new script. Speed is also just one of the levers; for the rest of the picture, read how to rank higher in Google.
Frequently asked questions
Is site speed really a ranking factor?
Yes. Google confirmed speed as a ranking signal in 2010 (desktop) and 2018 (mobile), and Core Web Vitals have counted through the Page Experience signals since 2021. Content relevance weighs more, but in a competitive field where the content is comparable, speed tips the balance.
What is a good load time for SEO?
Google treats an LCP of 2.5 seconds or less as “good”, measured at the 75th percentile of your real visitors. In practice that means your main content has to render within 2.5 seconds on a mid-range phone over 4G, not just on your office fibre.
What happened to FID?
FID (First Input Delay) was replaced by INP (Interaction to Next Paint) in March 2024. INP looks at all interactions during a visit instead of only the first one, which exposes slowness FID used to miss. The threshold for “good” is 200 milliseconds.
Will my rankings jump as soon as my site gets faster?
Not guaranteed, and rarely overnight. Speed is one signal among many. What you will notice immediately: fewer people bouncing, better ad quality scores, and a site that is ready to rank once your content and authority are in place.
Curious how fast your site could be?
We measure your current Core Web Vitals, show you where the gains are, and tell you honestly whether a rebuild or a tune-up makes more sense.
