How to test a website: the 4 types of website testing

01

1. Functional testing: does everything work?

Functional testing checks that every part of the site does what it should. Click through it like a visitor, then check the parts that are easy to miss.

• Links: no broken links or links pointing at the wrong page; a broken link checker finds them on a page in seconds
• Forms: required fields are enforced, wrong input shows a clear error, a sent form says so and the message arrives
• Menus, buttons, search, filters, sign-in and checkout all work
• Pages that should exist load, and missing pages show a helpful 404

02

2. Usability testing: is it easy to use?

Usability testing watches real people try real tasks, such as finding a price or sending a contact form, and notes where they hesitate or get stuck. Five people often reveal most of the big problems. No tool replaces this, but you can run it for free with colleagues, friends or customers and a screen share.

03

3. Performance testing: is it fast?

Performance testing measures how quickly pages load and respond. Google’s free PageSpeed Insights and Lighthouse in Chrome report load speed and Core Web Vitals for a page. Check the pages people land on most, on a phone-sized screen, and look for heavy images, layout that jumps while loading, and slow scripts. For high-traffic sites, load testing tools check how the server copes with many visitors at once.

04

4. Security testing: is it safe?

For sites handling payments or personal data, a professional security test (penetration test) goes further.

• HTTPS everywhere, with a valid certificate that isn’t about to expire
• No mixed content: every image, script and style loaded over HTTPS
• CMS, themes and plugins up to date, unused ones removed
• Forms protected against spam, and no sensitive data in page addresses
• Free scanners such as Mozilla Observatory and SSL Labs check headers and certificates

05

Also: compatibility and accessibility testing

Compatibility testing checks the site on the screen sizes and browsers people use: phones, tablets, laptops, and Chrome, Safari and Firefox. Most layout bugs only show at one width or in one browser, often Safari on iPhone. Accessibility testing checks that everyone can use the site, including people using a keyboard, a screen reader or larger text: contrast, labels, headings and focus. Automated checks find many accessibility problems; a quick keyboard pass finds more.

06

How to test your website for free

All of UICheck’s free tools are on its tools page and need no sign-up. A free account checks a page on 5 screen sizes, 5 times a day.

• Layout on every screen size: UICheck’s free responsive design checker and mobile-friendly test
• Broken links: UICheck’s free broken link checker
• Accessibility: UICheck’s free accessibility checker and color contrast checker, or axe DevTools
• Search basics (title, description, noindex): UICheck’s free meta tag checker
• Speed: PageSpeed Insights or Lighthouse
• Security: Mozilla Observatory and SSL Labs
• Usability: five people, five tasks and a screen share

07

A simple order to test in

1. 1Click through every key flow once by hand (functional)
2. 2Check every page on phone, tablet and desktop, in Chrome and Safari (compatibility)
3. 3Run broken link, accessibility and meta tag checks on every page
4. 4Measure speed on the most visited pages
5. 5Check HTTPS, updates and forms (security)
6. 6Watch a few people use it (usability), then fix and test again