Most customers will never tell you your website is slow, awkward on a phone or hard to read. They simply leave. Speed, mobile usability and accessibility are three of the least glamorous parts of a website, and three of the most important. This guide explains what each one means, how to check your own site for free, and the fixes that usually make the biggest difference.
Why these three matter together
They all come down to the same thing: can a real person, on whatever device they have, use your site without effort? Google says its Core Web Vitals measure real-world user experience, and that good results align with what its core ranking systems seek to reward. Google also uses the mobile version of your content for indexing and ranking, known as mobile-first indexing. And an accessible site is simply usable by more of your potential customers.
Website speed: what to measure
Google's Core Web Vitals are three measurements:
- Largest Contentful Paint (LCP) measures loading. Google suggests the main content should appear within 2.5 seconds.
- Interaction to Next Paint (INP) measures responsiveness when someone taps or clicks. Google suggests under 200 milliseconds.
- Cumulative Layout Shift (CLS) measures visual stability, meaning how much the page jumps around as it loads. Google suggests a score below 0.1.
How to check your speed for free
- PageSpeed Insights at pagespeed.web.dev tests any page and reports on Core Web Vitals.
- Google Search Console includes a Core Web Vitals report showing how your pages perform for real visitors, once you have enough traffic.
Test your home page and your most important service or product pages, and test the mobile results first.
Common causes of a slow site
- Huge images. Photos uploaded straight from a camera or phone are often many times larger than needed. Resize and compress them before uploading, and use modern formats where your platform supports them.
- Too many plugins or scripts. Every chat widget, tracking tool and social feed adds weight. Remove anything you do not use.
- Heavy page builders and themes that load far more code than the page needs.
- Slow or overloaded hosting.
- Autoplaying video or large sliders at the top of the page.
Fixes that help with layout jumping
If buttons move just as someone tries to tap them, that is layout shift. It is often caused by images without set dimensions, adverts or banners that load late, or fonts that swap in after the page appears. Reserving space for images and late-loading elements usually solves it.
Mobile: what good looks like
Google recommends responsive design, where the same page adapts to any screen. Whatever your setup, check these on your own phone:
- Readable text without pinching to zoom.
- Tap targets such as buttons and links that are large enough and not crammed together.
- A tap-to-call phone number if calls matter to your business.
- The same content as desktop. Google advises that your mobile site should contain the same primary content as your desktop site, since indexing comes from the mobile version. Use accordions or tabs to save space rather than deleting content.
- Simple forms. Fewer fields, the right keyboard for each field (number pad for phone numbers), and clear error messages.
- No intrusive pop-ups covering the page as soon as someone arrives.
A useful habit: once a month, find your own business on Google from your phone, tap through to your site and try to make an enquiry. If anything annoys you, it is annoying your customers too.
Accessibility basics
Web accessibility means people with disabilities can perceive, understand, navigate and interact with your website. That includes people who are blind or partially sighted, people with hearing loss, people with limited movement who use a keyboard instead of a mouse, and people with cognitive differences.
The recognised standard is the Web Content Accessibility Guidelines (WCAG) from the W3C. WCAG 2.2 has 13 guidelines organised under four principles (perceivable, operable, understandable and robust), with success criteria at levels A, AA and AAA. Level AA is the level most organisations aim for.
Quick accessibility wins
- Alt text on images. Describe what the image shows and why it matters. Decorative images can have empty alt text so screen readers skip them.
- Proper headings. Use one main heading per page and logical subheadings beneath it, not bold text styled to look like a heading.
- Colour contrast. Light grey text on white is hard for many people to read. WCAG sets a minimum contrast ratio of 4.5:1 for normal text at level AA.
- Do not rely on colour alone. If a form error is shown only in red, some visitors will miss it. Add a written message.
- Labelled form fields. Every field needs a visible label, not just placeholder text that disappears when someone starts typing.
- Keyboard navigation. Try using your site with only the Tab and Enter keys. You should be able to reach every link and button and see where you are.
- Descriptive link text. "View our bathroom fitting services" is clearer than "click here".
- Captions on videos that contain speech.
How to check accessibility
The W3C publishes a free Easy Checks guide for a first review. Automated tools can catch some issues, but they cannot catch everything, so a manual check with a keyboard and a screen reader is worth doing on your key pages.
A practical order of work
If you are not sure where to start, this order tends to give the best return for the effort:
1. Run PageSpeed Insights on your home page and top service page, on mobile. 2. Compress and resize your largest images. 3. Remove plugins, widgets and scripts you no longer use. 4. Check your site on your own phone and fix anything awkward to tap or read. 5. Fix colour contrast and add missing alt text. 6. Check every form has labels and works with a keyboard. 7. Set up Search Console so you can track improvements over time.
When to get help
Some fixes, like image sizes and alt text, are easy to do yourself. Others, like a heavy theme or slow hosting, may need a developer or a rebuild. If your site needs deeper work, our website development team builds with speed, mobile and accessibility as the starting point, and our SEO service covers the technical checks that keep a site healthy. Contact us if you would like a second opinion.
Frequently asked questions
Does website speed affect Google rankings?
Google says good Core Web Vitals align with what its core ranking systems seek to reward, alongside other page experience factors. Content relevance still matters most, but a slow site loses visitors whatever its ranking.
What is a good PageSpeed score?
Focus on the three Core Web Vitals rather than the single headline score: LCP within 2.5 seconds, INP under 200 milliseconds and CLS below 0.1.
Do I need a separate mobile website?
No. Google recommends responsive design, where one site adapts to every screen size.
Is accessibility only about blind users?
No. It covers a wide range of needs, including hearing, movement and cognitive differences, and it also helps people using a phone in bright sunlight or with one hand.
Can an accessibility plugin or overlay fix my site?
Overlays cannot fix underlying problems in your page structure, content or forms. Fixing the site itself is the reliable approach.