A website that does not convert nearly always suffers from the same mistakes: a vague message, poor speed, no social proof or an overlong form. These 10 problems account for 80% of the non-conversion causes we have identified while auditing more than 150 small business and trade websites since ConvertiLab started.
55% of visitors decide in under 15 seconds whether to stay on a website or leave. If your site makes even one of the mistakes below, you are losing customers every day.
Start by checking your website's design score for free before you read this guide, and you will know exactly where to begin.
Why does a non-responsive website drive away 62% of visitors?
A non-responsive website drives visitors away because 62% of web traffic comes from a smartphone in 2026. A site that does not adapt to a mobile screen is unreadable, hard to tap and comes across as unprofessional, so the visitor leaves in under five seconds. Google also penalises these sites in its rankings (mobile-first indexing).
Symptoms to look for:
Immediate fix: open Chrome DevTools (F12) and switch to mobile view. If the page is unreadable, that is an emergency to deal with before anything else.
What does a slow loading time do to your sales?
A slow loading time hits your sales directly because 53% of visitors abandon a mobile site if it takes more than three seconds to load. Every extra second cuts the conversion rate by 7% according to Google. In plain terms: a site that loads in five seconds instead of two can cost you 20% of your potential leads.
Common causes of slowness:
Test your site on Google PageSpeed Insights, minimum target: 80/100 on mobile.
Why must your home page message be understood in three seconds?
Your home page message must be understood in three seconds because that is all the time a visitor gives you to decide whether they are in the right place. If your value proposition is not immediately clear, they go and find a competitor. A vague or generic message creates an uncertainty most prospects will not take the time to resolve.
Your value proposition must answer in one sentence: who you are, what you do, who it is for and what concrete benefit it brings.
How does a poorly written call to action lose you prospects?
A poorly written call to action loses prospects because a visitor who does not know exactly what to do next does nothing. Vague buttons such as "Learn more" or "Send" do not trigger action. A precise, benefit-led call to action ("Get my free quote within 48 hours") consistently earns more clicks than a generic button.
Rules for calls to action that convert:
On the websites we build at ConvertiLab, the main call to action is always visible within the first 200 pixels of the page. It is the single rule with the biggest effect on quote requests.
How many fields should a contact form have to convert?
A contact form that converts should have no more than three fields at first contact: first name, email (or phone) and one question about the need. A HubSpot study shows that a three-field form converts twice as well as an eight-field form. Every extra field is a point of friction that sends part of your prospects away.
What to ask for at first contact:
What NOT to ask before the meeting: postal address, company registration number, exact budget, precise deadline, company size.
Why does generic content penalise your website on Google?
Generic content penalises your website because since 2023 Google has been measuring content quality and originality through its Helpful Content updates. Copied and pasted text, or text churned out with no real experience behind it, gets detected and gradually demoted. Your visitors feel it too: generic content builds no trust.
Signs of content that is holding your website back:
The fix: add your real figures, your real clients, your real photos. That is exactly what a competitor copying and pasting from AI cannot duplicate.
How do customer reviews shape online buying decisions?
Customer reviews shape online buying decisions because 92% of consumers read reviews before choosing a supplier, and 84% trust online reviews as much as a personal recommendation. Without visible social proof on your website, you are asking prospects to take your word for it, and most will not.
Social proof to display, in order of impact:
Place these elements immediately after your main call to action so the reassurance lands at the moment of decision.
What effect does HTTPS have on visitor trust and SEO?
HTTPS has a double effect: it stops Chrome showing the "Not secure" warning that drives away 85% of visitors, and it has been a confirmed Google ranking factor since 2014. A site still on HTTP in 2026 looks unprofessional and potentially dangerous to modern browsers.
The fix: switch on the SSL certificate from your host (free with almost every host since Let's Encrypt). On Vercel or Netlify it is enabled automatically.
Why does confusing navigation push up your bounce rate?
Confusing navigation pushes up your bounce rate because a visitor who cannot find what they came for in two or three clicks leaves straight away. That behaviour tells Google your site does not answer the query, which erodes your ranking over time. An unreadable menu or an overly deep structure is a direct cause of a high bounce rate.
The most common navigation mistakes:
The three-click rule: every essential piece of content must be reachable from the home page in no more than three clicks.
Which tools should you install to measure your website's performance?
To measure your website's performance you need at least Google Analytics 4 for traffic and conversions, Google Search Console for search rankings, and Microsoft Clarity to see how visitors behave. All three are free and are enough to make concrete improvement decisions.
Without this data you do not know which page brings in your enquiries, or why visitors leave without converting.
Checklist: the 10 points to check on your website
| Criterion | How to check | Priority |
|---|---|---|
| Mobile responsive site | Chrome DevTools mobile view | Critical |
| Speed above 80/100 | Google PageSpeed Insights | Critical |
| Clear message without scrolling | Three-second test with someone else | High |
| One main call to action visible | Review every page | High |
| Form with 3 to 4 fields max | Count the fields | High |
| Content with concrete examples | Critical read-through | Medium |
| Customer reviews on display | Check the home page | High |
| HTTPS enabled | URL starts with https:// | Critical |
| Navigation with 5 to 7 items max | Count the menu links | Medium |
| Analytics installed and configured | Google Analytics 4 active | High |
Fixing the four "Critical" points is usually enough to double the conversions of an existing website.
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Frequently asked questions about website conversion
What is a good conversion rate for a brochure website?
A good conversion rate for a brochure website is between 2% and 5%. Below 1%, the site has a structural problem (vague message, missing call to action or an overlong form). Above 5%, the site is very well optimised. The average small business brochure website sits around 1.5% to 2%.
How long does it take to see results after fixing these mistakes?
Technical fixes (speed, HTTPS, responsive design) have an immediate effect on the user experience and show up in SEO within 2 to 4 weeks. Content and call to action fixes show results within days if your site already has traffic. Organic search can take 2 to 3 months to reflect the improvements fully.
Should you rebuild the whole website or can you fix it in place?
In most cases an existing website can be fixed in place. Only sites built on very limited platforms (an old Wix version, a Flash site and so on) need a full rebuild. The 10 mistakes listed in this guide can be fixed on any CMS or bespoke website.
