After LaunchPage speed · Core Web Vitals · LCP · INP · CLS · CDN
Page speed · Core Web Vitals
Page speed is how long it takes from tapping a link until the page appears and can be used, and Core Web Vitals are the three metrics Google uses to measure it.
It's how long it takes for a customer to walk in, sit down and get a menu. Keep them waiting too long and they just leave.
A little more detail
Google's Core Web Vitals are three metrics: how long the largest content takes to appear (LCP, recommended within 2.5 seconds), how fast the page responds after a tap (INP, recommended within 0.2 seconds), and how much the layout suddenly shifts (CLS, recommended 0.1 or less).
Slowness usually comes from heavy photos, too much third-party code (ads, chat, widgets) or a slow server. Simply shrinking photos often makes a big difference.
A CDN is a service that copies your website files to servers in many regions and delivers them from the one closest to each customer. It helps your site load fast even for faraway customers.
What are the Core Web Vitals thresholds in seconds?
Google rates a page "Good" when LCP is 2.5 seconds or less, INP is 200 milliseconds (0.2 seconds) or less, and CLS is 0.1 or less. A page passes Core Web Vitals only when all three metrics are "Good."
The thresholds are judged not on a single visit but at the 75th percentile of visits. Put simply, at least 75 out of 100 customers must get a speed within the threshold for the page to be "Good." Mobile and desktop are measured separately.
There used to be a metric called FID that measured only the response to the first click, but in March 2024 it was replaced by INP, which looks at the response to every click and tap. If you see FID thresholds in older articles, remember they no longer apply.
Swipe the table sideways to see more
| Metric | What it measures | Good | Needs improvement | Poor |
|---|---|---|---|---|
| LCP (Largest Contentful Paint) | How long the largest photo or block of text on screen takes to appear | 2.5 seconds or less | Over 2.5 seconds to 4 seconds | Over 4 seconds |
| INP (Interaction to Next Paint) | How long the screen takes to respond after a tap or typing | 200 milliseconds or less | 200–500 milliseconds | Over 500 milliseconds |
| CLS (Cumulative Layout Shift) | How much the page suddenly jumps while someone is reading | 0.1 or less | Over 0.1 to 0.25 | Over 0.25 |
How do I test my website's speed with PageSpeed Insights?
Just enter your address into PageSpeed Insights, Google's free tool, and it measures your site right away. The results are split into two parts, real visitor data and a lab diagnosis run by a machine, and the key is to read them separately.
- 01Go to pagespeed.web.dev, enter your website's address and click "Analyze."
- 02When the results appear, look at the "Mobile" tab first, because most customers visit on their phones.
- 03In the "Discover what your real users are experiencing" section at the top, check whether LCP, INP and CLS are "Good." This is the last 28 days of data from Chrome users, so it's the most reliable.
- 04If you don't get many visitors, the real-user section may say "No data." In that case, use the "Diagnose performance issues" score below it.
- 05Take a screenshot of the image and JavaScript improvement items under the diagnosis, so you can ask your agency for exactly what's needed.
- 06Don't stop at the home page. Test the pages customers visit most, like your menu, booking and directions pages, one by one.
Why does my PageSpeed score change every time I test?
The diagnosis score at the bottom is calculated by Google's servers reloading your page at that moment, so it goes up and down by a few points depending on server load and the network. It's better to look at the trend over several tests than at a single number.
If your page loads outside code, such as ad, chat or review widgets, results swing even more depending on those services' servers. If your score suddenly drops, suspect the outside code you added most recently first.
You don't need to chase a perfect 100. Google itself says that chasing a perfect score just for search may not be the best use of your time. If "Discover what your real users are experiencing" shows "Good," your site is in good shape.
It's also normal for the real-user data at the top and the diagnosis score below to disagree. The real-user data is collected over several weeks from many customers' phones and connections, while the diagnosis is a single re-test under fixed conditions. When they differ, trust the real-user data first, since that's what your customers actually experienced.
What usually makes a website slow?
Most small-business websites get slow because of things added one at a time after launch. Often a site is fast at first, then slows down over a few months as photos and widgets pile up.
Each cause hurts a different metric. A heavy main photo hurts LCP, heavy outside code hurts INP, and photos without set dimensions or banners that load late hurt CLS.
The surest way to find the cause is to remove things one at a time. Turn off the widget you added most recently, test again, and the numbers will show how much it slows the page. If you really need that widget, you can also have it load only after the first screen has fully appeared.
- Original photos from your phone uploaded without being resized
- An autoplay video or a large slideshow on the first screen
- Several widgets added, such as live chat, an Instagram feed or reviews
- Unused tracking code or old ad code still on the site
- Loading many different fonts, or using a slow server far from your customers
What should I ask for when I hire someone to speed up my website?
Rather than "Make it faster," set a goal like "Get this metric on this page to Good." That way you can compare before and after, and you have a clear standard for when the job is done.
A common mistake is deleting content you really need just to raise the score. If the site got faster because the booking button or map was removed, your customers actually lose out. Checking only on a computer and never on a phone is another frequent mistake.
- A list of pages to improve and the target metric (e.g. home page mobile LCP "Good")
- Screenshots of PageSpeed Insights results before and after the work
- A list of the outside code and widgets currently on the site, with the essential ones marked
- Whether new photos are resized automatically when uploaded
- Who checks, and when, if speed gets worse again during maintenance
How can a small business keep its website fast?
The first screen makes the biggest difference. Just making the one main photo customers see first lighter, and loading the photos below the first screen only as people scroll, makes the site feel much faster.
A Pilates studio could replace the class video on the first screen with a main photo and move the video down to a "Take a look at our classes" section. A restaurant could write out its menu as text with photos of just its signature dishes instead of dozens of menu-board photos. The page gets faster and search engines can read it better.
If shrinking photos doesn't help much, suspect the server. If the diagnosis says the server responds slowly, check your hosting plan and server location. Using a CDN, which delivers files from a location close to your customers, is another option.
ISSYMO builds image optimization and a fast first screen into the basic setup before launch, and with a maintenance subscription we check every month that no new heavy images have crept in.
For example
- A restaurant's first screen had a large video, so on mobile data visitors stared at a blank white screen for a long time. After switching to a main photo, it loads instantly.
- When an ad banner loads late and pushes the text down while you're reading, that's a CLS problem.
Just check these
- You've tested your address on mobile in Google PageSpeed Insights
- There are no original-size photos or large videos on the first screen
- Unused widgets · tracking codes have been removed
Does my business need it?
It applies to every website, and matters especially if you have lots of photos or run ads.
At ISSYMO
The basic search and AI visibility setup includes image optimization and a fast first screen. With a maintenance subscription, we check your speed every month to make sure the first screen hasn't slowed down.
See maintenanceFAQ
Sources
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