Web developmentInteractive
The hidden cost of a slow website and how to optimize its performance
Every second of load time takes visits and sales with it. Simulate how much your business loses to slowness and what to do so your site loads in under a second.
By Keyner Trillos· Updated
In short
- According to Google, when load time goes from 1 to 3 seconds the probability of a visitor bouncing rises 32%; from 1 to 5 seconds, it rises 90%.
- A Deloitte study found that improving mobile speed by just 0.1 s increased retail conversions by 8.4%.
- Google considers a site good with an LCP up to 2.5 s, INP up to 200 ms and CLS up to 0.1.
- The most common causes are heavy templates, plugins, unoptimized images and slow hosting.
A slow page never warns you. There's no error on screen and no email saying “you lost a customer”. People just close the tab and go to the next result. That's why slowness is the most expensive cost that doesn't show up in any report.
What the data says
Simulate what slowness costs you
Enter your real numbers: monthly visits, conversion rate and the average value of a customer. Then move the load time and see how many sales get lost on the way.
Why websites get slow
- Multipurpose templates. They ship code for a hundred features even if you use three.
- Piled-up plugins. Each one adds scripts and database queries.
- Unoptimized images. Multi-megabyte photos served the same to phones and desktops.
- Cheap shared hosting. Many sites fighting over the same server.
- Third-party scripts. Chats, pixels and widgets that block loading.
How to measure your site today (in 5 minutes)
- Go to PageSpeed Insights and type your site's address.
- Look at the Mobile tab first: that's where most of your visits are.
- Check the real-user data (if shown): LCP, INP and CLS.
- Find the LCP element: it's almost always the main image or headline.
- Repeat the test with your most visited product or service page.
| Metric | What it measures | Good |
|---|---|---|
| LCP | How long the main content takes to appear | ≤ 2.5 s |
| INP | How fast the page responds to taps and clicks | ≤ 200 ms |
| CLS | How much the layout jumps while loading | ≤ 0.1 |
How we load in under a second
On our projects, mobile PageSpeed goes from an average of 46 to 98 out of 100. There's no trick: it's a sum of custom decisions.
- Original code, with no visual builders or plugins you don't need.
- Images in modern formats and at the exact size of each screen.
- Pages generated ahead of time and served from servers close to your customer.
- Deferred loading of everything that isn't visible when the page opens.
- Measuring before launch, not after.
One example: GMX Gaming went from 4.9 s to 0.59 s by replacing a limited WordPress site with a custom platform, and automated its registrations.
Frequently asked questions
How long should a web page take to load?
Ideally the main content appears in under 2.5 seconds on mobile (LCP). Our sites usually load it in under one second.
Does speed affect Google rankings?
Yes. Core Web Vitals are part of the page experience signals, and a fast site also keeps more visitors, which improves conversion.
Sources
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