Why do I score low on PageSpeed and what's behind it
A low PageSpeed score feels frustrating. You adjust all sorts of things, but the meter stays red or orange. In this guide, I show you the problems we encountered at our own website theseo.co.uk, why cookies banners and translation plugins demolish your score, and how you can get peace of mind in your report with a few targeted plugins and small php snippets without sacrificing design.
First, understand what exactly PageSpeed is telling you
Many people stare blindly at a number. In reality, PageSpeed is a summary of several components. Some things can be felt directly by visitors, while others are mostly theoretical. So you don't necessarily need to head towards a hundred to have a fast and quiet website, but a very low score does indicate real problems.
| Section | What it means | What you are steering for |
|---|---|---|
| First content load time | When someone first sees something on the screen | Important for first impressions and peace of mind |
| Load time biggest element | When the main image or text is | Lighten images and hero blocks |
| Interactivity | How quickly buttons react when someone clicks | Defer scripts, limit heavy plugins |
| Layout shift | Or parts jump during loading | Fixed heights, no late banners or fonts |
Test your homepage and at least one key landing page on mobile and desktop.
Page I am testing Mobile score Desktop score Key warnings Most important recommendations Which part bothers me most as a visitor
Get the basics right before tweaking
For many clients with older websites, we saw that small optimisations did little as long as the basics weren't right. Old php versions, junk in the database and too many plugins push your score down even before you look at images or scripts.
Progress basic step
An administrator who works specifically with WordPress makes a big difference. Choose a party with servers close to your visitors and a cache layer on the server side. That gives you a head start even before you think about plugins.
Remove old revisions, expired transients and empty tables. You do this safely with a maintenance plug-in or manually after backing up. We only really saw a difference with our customers when we cleaned up their databases and they were no longer full of leftovers from old plugins.
Recognise the real culprits scripts, cookie banners and translation plugins
The biggest drops in the PageSpeed score of theseo.co.uk were not due to the theme, but to extra scripts. Cookie banners, tracking scripts, chat widgets and (at other clients' translation plugins) in particular were heavier than you might think at first glance.
Every cookie banner pastes extra javascript and css on top of your page. Some solutions even load external scripts before the rest of the page is ready. Choose a light banner, turn off animations and load it only after the main content is shown. In extreme cases, it's better to switch to a simpler system that loads fewer integrations.
Run through the list of scripts and decide for each item whether it can stay.
Script or plugin name Purpose it serves Is it still actively used yes or no Is there a lighter alternative Should it only load on a few pages Decision to remove, limit or keep
Use a few targeted performance plugins and small php snippets
At theseo.co.uk, we did a lot of testing. The biggest gains came from a combination of one good cache plugin, an image optimisation plugin and a few small php functions via Code Snippets. Not ten different performance plugins mixed together but a calm set with clear tasks.
Use one modern cache plugin with functions for page cache, script optimisation and browser cache. Turn on only basic functions first. Then quietly test additional options like deferring javascript. Setting it too aggressively can also give errors, especially with forms and web shops.
Install a plugin that automatically resizes new uploads and preferably converts them to a modern file format. Combine this with lazy load so that images are loaded only when they come into view.
Instead of placing separate functions in a theme, we opted for the Code Snippets plugin. This allows you to add safe php snippets without messing around in files. Think of disabling emoji scripts, oEmbed functions or query strings on static files.
Paste this into a new snippet and activate it on the whole site. Then retest your PageSpeed report.
// Disable emoji script
remove_action('wp_head','print_emoji_detection_script',7);
remove_action('wp_print_styles','print_emoji_styles');
// Disable OEmbed script if you don't use it
remove_action('wp_head','wp_oembed_add_discovery_links');
remove_action('wp_head','wp_oembed_add_host_js');Lighten hero blocks and images without getting ugly
Our own homepage initially had a heavy header with lots of layers, shadows and large backgrounds. This looked nice but depressed the PageSpeed score and especially the experience on mobile. By using fewer effects and better-scaled images, the style remained the same but everything felt much lighter.
PageSpeed looks extra strictly at the first screen someone sees. Big videos, sliders with three layers of text and multiple heavy icon sets take up a lot of time. Replace that with one calm headline, short text and a light image.
Use a different size for mobile than for desktop when necessary. This way, you avoid loading a picture that is far too wide for small screens. This immediately saves in loading time and report score.
Is there only one clear message in the first screen Is the background a light image instead of a heavy video Does the font load quickly and without jumps Are buttons instantly clickable without delay Is the first screen on mobile as quiet as on desktop
How we improved the PageSpeed of theseo.co.uk
To make it concrete, a brief summary of what we did at our own website. Not perfect, but honest. These are the steps that gave the most difference.
- Too many scripts and styling in blocks on the homepage.
- A cookie banner that didn't slide in until late and shifted the layout.
- Images that were larger than necessary and did not always use lazy load.
- Multiple small scripts for tracking and tools side by side.
- Layout simplified and certain effects kept only on desktop.
- One performance plugin chosen and set quietly.
- Cookie banner replaced and set to block less.
- Images re-uploaded in lighter shapes and lazy load activated.
- Tracking cleaned up and run through one central layer.
Use this structure to define your approach for each website.
Main pages I optimise Key issues from the PageSpeed report Actions for hosting and base Actions for plugins, cookie banner and translations Actions for images and hero block Actions for scripts and tracking Date I re-measure Target score for mobile and desktop
Check your PageSpeed score and how it feels in practice
After all the steps, it's all about two things. A report that no longer flashes red and a website that feels calm. You finish this process with a short re-test and a trial with real users or colleagues.
Answers to questions about a low PageSpeed score
No. A hundred looks nice on a screenshot but is not a goal in itself. Aim for a stable green or high orange score while keeping the website calm and usable. Some choices like a cookie banner or certain statistics are necessary and do cost something in terms of score.
Mobile testing is more rigorous. The test assumes a slower device and a slower connection. So anything heavy like images, scripts, cookie banners and translation layers will be penalised harder. Therefore, always start with your mobile experience.
A good performance plugin helps tremendously but cannot completely hide wrong choices. If you have twenty heavy plugins, three chat widgets and an oversized hero video, it will remain slow. Think of performance plugins as a tool, not a panacea.
A banner always adds something to load time because additional scripts and styles are loaded. The impact depends on how heavy the solution is and when it loads. Choose a light one and set it so that the most important content comes first. Then the damage will be limited.
Then test with real users. Sometimes a form, a search function or a specific page in particular is slow while the report shows average values. Optimise those crucial moments and look beyond just the report.
You now know why you score low on PageSpeed and what you can do about it
You've seen that a low PageSpeed score is almost never due to one thing. It's the sum of hosting, basic settings, scripts, cookie banners, translation plugins, images and choices in your design. By cleaning up, testing and remeasuring step by step, you will quietly work towards a website that feels right to visitors and sends clearer signals to search engines and ai systems.
Now grab your baseline, pick one page and make the first improvements. Only then move on to the next layers. This way, you stay in control and PageSpeed becomes a tool instead of a source of stress.