Launching a new website, or making big changes to an existing one, is a major milestone. After months of planning, design, and development, it’s natural to want to get it live as quickly as possible and start seeing results.
But what happens in the final stretch often decides how well that website performs. A form that doesn’t send, a page that loads slowly on mobile, or a checkout that breaks in one browser can quietly cost you enquiries and sales, and you may not find out until the damage is done.
That’s where website testing comes in. If you’re responsible for a website, you’ll know how many moving parts there are, and it can be hard to know what to check, how thoroughly, and when. That’s why having a clear testing approach takes a lot of that uncertainty away.
In this blog, we’ll explore what website testing is, why it’s important, the main types of testing to know about, and how to test a website effectively before and after launch.
What is website testing?
Website testing is the process of checking that a website works as it should for everyone who uses it, on every device and browser, before and after it goes live. It covers how the site functions, how fast it loads, how easy it is to use, how secure it is, and how well it can be found in search.
Testing typically looks at two sides of a website:
- The technical side – whether pages load properly, features work, integrations connect, and the site performs well under real conditions
- The user side – whether people can find what they need, understand the content, and complete key actions like sending an enquiry or making a purchase
Testing isn’t a one-off job at the end of a project, either. The most effective websites are tested throughout development, before launch, and regularly once they’re live, because updates, new content, and plugin changes can all introduce new issues.
Why is website testing important?
Your website is often the first place people go to find out about your business, so problems can be costly. Here are some of the key reasons why website testing is so important:
1. It protects your leads and sales
Every broken link, failed form, or confusing step in a user journey is a missed opportunity. Most visitors won’t tell you something’s wrong. They’ll simply leave and go elsewhere.
Testing helps you catch issues such as:
- Contact or quote forms that don’t send or don’t reach the right inbox
- Checkout or booking processes that fail on certain devices
- Buttons or links that don’t work
- Error messages that confuse rather than help
By finding these before your customers do, you protect the enquiries and sales your website is there to generate.
2. It gives everyone a consistent experience
People visit your website from a huge range of devices, screen sizes, and browsers. A page that looks perfect on a large desktop monitor can look very different on a mobile device or a different browser.
Thorough testing makes sure your website works for all of them, so no visitor gets a second-rate experience. It’s especially important for organisations whose audiences are varied, such as colleges, charities, or public-sector bodies.
3. It supports your search visibility
Search engines reward websites that are fast, mobile-friendly, and easy to crawl. Technical issues like slow pages, broken links, missing meta data, or indexing errors can all hold back your rankings without you realising.
Testing helps you spot these problems early and using tools you may already know, like Google Search Console, PageSpeed Insights, and Screaming Frog, can all help you see how your site performs from a technical point of view.
4. It reduces risk and cost
Fixing a problem before launch is almost always quicker and cheaper than fixing it afterwards, when it may have already affected customers, data, or your reputation. Testing also reduces the risk of security issues, broken integrations, and compliance problems.
For businesses that handle personal data or take payments online, this is particularly important. A small oversight can have big consequences.
5. It gives you confidence at launch
Launch day can be stressful, especially if stakeholders are watching. A clear testing process means you can go live knowing the website has been checked properly, with any issues logged, prioritised, and fixed.
That confidence carries on after launch too, because you’ll have a baseline to measure any future changes against.
What are the main types of website testing?
There are several types of website testing, each designed to check a different part of how your site works. Here are the main ones to keep in mind:
Functional testing
Functional testing checks that every feature does what it’s supposed to. That includes forms, search, filters, logins, booking systems, payment gateways, and any integrations with your CRM or other platforms.
A good functional test follows real user journeys from start to finish, such as submitting an enquiry and checking it arrives, or completing a test purchase and receiving the confirmation email.
Browser and device testing
Browser and device testing makes sure your website looks and works correctly across different browsers (like Chrome, Safari, Edge, and Firefox) and common devices like desktop, laptop, tablet, and mobile.
It typically checks for:
- Layout issues or broken elements
- How content adapts to different screen sizes
- Whether menus, buttons, and forms work consistently
The most efficient approach is to use your analytics data to prioritise the browsers and devices your visitors actually use, then test those thoroughly on real devices.
Speed and performance testing
Speed has a direct impact on both user experience and search rankings. Performance testing measures how quickly your pages load and respond, and highlights what’s slowing them down.
Tools like PageSpeed Insights, Google Lighthouse, and GTmetrix can help you identify issues such as:
- Large or unoptimised images
- Slow server response times
- Unnecessary scripts or third-party tags
- Poor Core Web Vitals scores
User experience (UX) testing
UX testing looks at how real people use your website, including what they click, how far they scroll, where they get stuck, and where they leave. It helps you find friction that technical tests won’t pick up.
Common UX testing methods include:
- Heatmaps and session recordings
- A/B or split testing of layouts and content
- User journey reviews and feedback sessions
- User acceptance testing (UAT) with a representative group of your users
The aim is to remove anything that makes it harder for people to find what they need or to take action.
Accessibility testing
Accessibility testing checks that your website can be used by everyone, including people who use screen readers, keyboard navigation, magnification, or voice control. It covers things like colour contrast, alt text, heading structure, form labels, and focus states.
As well as being the right thing to do, accessibility is a legal requirement for public-sector websites and good practice for every organisation. Our post on designing for accessibility covers the fundamentals you need to know.
Security testing
Security testing looks for weaknesses that could put your website or your users’ data at risk. This includes checking that your SSL certificate is in place, software and plugins are up to date, forms are protected against spam and abuse, and admin areas are properly secured.
We’ve shared some key ways you can improve your website security in our blog.
SEO checks
Completing SEO checks makes sure your website is set up to be found in search engines. It typically includes:
- Checking page titles, headings, and meta descriptions
- Reviewing internal links and redirects
- Testing structured data
- Identifying crawl errors and indexing issues in Google Search Console
If you’re moving to a new website, it’s especially important to check that old URLs redirect correctly, so you don’t lose the rankings you’ve already built.
How do you test a website?
The right approach depends on the size and complexity of your website project, but the most effective testing follows a similar process. Here are some of our top tips on how to test a website effectively:
- Plan what to test – start by listing your key pages, user journeys, devices, and browsers, and use your analytics data to decide what matters most.
- Test throughout the build – check features and functionality as they’re being developed, rather than leaving everything to the end.
- Run a full pre-launch check – work through functionality, speed, devices, accessibility, security, and SEO, and be sure to log every issue with clear priorities.
- Involve real users – ask a small group of people from your target audience to complete key tasks and get them to share their feedback with you.
- Retest after fixes – once you’ve fixed an issue, make sure each it works as it should and hasn’t caused new problems elsewhere.
- Keep testing after launch – ensure you continue to monitor site performance, run regular checks after any updates, and use your data to find new ways to improve your site.
Our checklist for launching a new website is a useful companion to this process.
Need help with your website testing?
The best websites aren’t just well-designed and well-built, they’re thoroughly tested. While good web design and development lay the foundations, it’s testing that makes sure a website works for every user, on every device, every time.
By building testing into every stage of your project, from early development through to launch and beyond, businesses can catch problems early, protect their leads and sales, and give their users a website they can rely on.
At Fifteen, we combine thorough website testing, user-centred UX, and experienced web development to make sure the websites we build perform from day one. From cross-device and browser testing, to user acceptance testing with real people and in-depth SEO audits, our expert team helps businesses launch websites that work exactly as they should.
Get in touch with us today to discuss how we can help build a site that encompasses specialist website testing so you can deliver an experience your customers can depend on.