Updated: 7 November 2026 · Web Performance · Own Data
A website counts as slow when its main content takes more than 4 seconds to appear on mobile: Google rates that as "poor", and anything under 2.5 seconds as "good". In October 2026 I measured 60 independent business websites in Alcorcón: 52 of them (87 %) took more than 4 seconds, the median was 9.1 seconds and only 3 came in under 2.5. How many customers yours is costing you can't be known without your own data, but you can estimate it with your own analytics, and most of the causes can be fixed in an afternoon.
For context: I'm Adrián Rubio and I sell web design, so I have an interest in you rebuilding your site. That is why I start with what can be fixed without rebuilding it, and then say when a rebuild is worth it.
What it means for a website to be "slow"
The metric Google uses is called LCP (Largest Contentful Paint): the time until the largest element on the screen appears, usually an image or a headline. It is the closest thing to "when it feels like the page has loaded". Google's thresholds, measured on mobile:
| LCP | Google rating |
|---|---|
| Up to 2.5 seconds | Good |
| Between 2.5 and 4 seconds | Needs improvement |
| More than 4 seconds | Poor |
A site can also feel slow for other reasons (content jumping around as it loads, or not responding when you tap), but LCP is the first number to look at.
The Alcorcón data
For the study digital snapshot of Alcorcón 2026 (in Spanish) I reviewed the websites of the city's independent businesses. Of the ones that worked, I measured 60 with Lighthouse, Google's tool, in simulated mobile mode on a 4G connection:
| Indicator | Result |
|---|---|
| Average performance score (out of 100) | 62 |
| Sites scoring 90 or more | 5 of 60 (8 %) |
| Sites scoring below 50 | 13 of 60 (22 %) |
| LCP, median | 9.1 seconds |
| Sites with LCP above 4 seconds | 52 of 60 (87 %) |
| Home page weight, median | 3.4 MB |
For comparison: arubeus.com scores 94 on mobile and 99 on desktop, and the demo templates score between 92 and 95. I don't say this to boast, but to show that a high score is achievable without tricks. These are aggregated results: I don't name sites or businesses. Because the measurements are simulated, the same site can score slightly differently in another test.
How many customers it costs you: how to estimate it with your data
There is no universal "one extra second = X % fewer sales" figure that I could give you without making it up. What you can do is estimate it with your analytics:
- Monthly mobile visits to your website (Google Analytics or Search Console).
- The percentage of those visits that call, write or book. If you don't measure it, measure that first.
- Compare the contact rate of mobile visits with that of desktop visits. If mobile clearly converts less, part of the difference may be down to speed (and to the phone number not being tappable with a single touch).
An example with numbers made up to illustrate the method, not real data: if you get 400 mobile visits a month and 2 % get in touch, that is 8 contacts. If fixing the site raised that to 3 %, it would be 12. Those 4 extra contacts, multiplied by what a customer is worth to you, are the cost of the slowness. Do the sum with your own figures.
And there is a cost that doesn't show up in analytics: someone searching on their phone for a service in Alcorcón sees several results and moves on to the next one if yours doesn't load. They never even reach your statistics.
Why a local business website is usually slow
| Cause | How to fix it | Who can do it | Effort |
|---|---|---|---|
| Huge, uncompressed images | Resize, compress and use modern formats (WebP) | You, with a free tool | An afternoon |
| Background video on the home page | Remove it or replace it with an image | You or whoever has the site | Minutes |
| Heavy template with lots of plugins | Deactivate the ones you don't use; check which ones load on every page | You or whoever maintains the site | Hours |
| Sliders and animations on load | Replace with an image and a headline | Whoever edits the site | Hours |
| Cheap shared hosting | Change plan or provider | You | A day plus the migration |
| Lots of third-party scripts (chat, pixels, maps) | Load only the necessary ones, and after the first interaction | Whoever manages the site | Hours |
| Heavy web fonts | Use few and preload the main one | Whoever edits the site | Hours |
In the snapshot study, half of the sites weighed more than 3 MB on the home page alone. With optimised images and no background video, that weight drops a lot without touching the design.
What you can do in an afternoon without touching code
- Measure your starting point with the free tool Check your website or with Google's PageSpeed Insights. Note down the score and the LCP.
- Compress the images on the home page and the main pages. A multi-megabyte image for a photo that displays small is the most common mistake.
- Remove the background video and the sliders from the home page.
- Deactivate the plugins you don't use, if your site runs on WordPress.
- Turn on caching (there are free options) and any compression your hosting offers.
- Measure again. If the LCP drops below 4 seconds, you are already out of the "poor" zone.
For more on speed in general, see mobile website speed: why it's costing you customers (in Spanish).
When it's worth rebuilding the website
Optimising is usually enough. A rebuild is worth it when:
- Even after optimising, the LCP stays above 4 seconds because the foundation (template, builder, hosting) is heavy.
- Besides being slow, the site doesn't look right on mobile, doesn't let people call with one tap or is out of date.
- Maintaining the plugins and updates costs you more than a simple, fast site would.
In that case, before asking for quotes read web design for small businesses: what to ask for and how much it costs (in Spanish), and if you are in the area see web design in Alcorcón (in Spanish). If you decide to migrate, do it without losing rankings with this SEO migration guide.
Frequently asked questions about slow websites
How long should a website take to load?
The main content should appear in under 2.5 seconds on mobile, which is the threshold Google considers good. Between 2.5 and 4 seconds "needs improvement", and above 4 it is "poor".
Does speed affect SEO?
Yes, speed is part of Google's page experience signals, although it is not the heaviest factor: content and links remain the main ones. A slow site also loses visits through people leaving, which is a separate effect from rankings.
Are Wix and WordPress slow?
Not by definition. It depends on the template, the plugins, the images and the hosting. A lightweight WordPress installation can be fast, and a site built with another system can be heavy. What matters is measuring your specific site.
How do I measure my website's speed?
With Check your website, with PageSpeed Insights or with Lighthouse in Chrome. Always measure in mobile mode, which is the most demanding scenario, and repeat the test several times because the result varies.
What is LCP?
It is the time until the largest element on the screen appears (an image or a headline). It is Google's measure of "when the page seems to have loaded". Good: under 2.5 seconds.
In summary
87 % of the 60 Alcorcón websites I measured took more than 4 seconds on mobile. The usual culprits are heavy images, background videos and overloaded templates, and it can almost always be improved in an afternoon. Measure first, fix the cheap things and rebuild the site only if that isn't enough. If you want me to look at it with you, write to me or see digital marketing in Alcorcón (in Spanish).
