Web Accessibility
Build websites everyone can use. It's the law.
Web accessibility means building sites that work for people with disabilities. It is a legal requirement in the UK and EU, and it makes your site better for everyone.
Why It Matters
Accessibility by the numbers
What is Web Accessibility?
Web accessibility is the practice of designing and building websites so that people with disabilities can perceive, understand, navigate, and interact with them effectively.
Who benefits from accessible websites?
- +Visual impairments - users who are blind or have low vision and rely on screen readers or magnification
- +Hearing impairments - users who are deaf or hard of hearing and need captions or transcripts for audio and video
- +Motor disabilities - users who cannot use a mouse and navigate entirely by keyboard or assistive devices
- +Cognitive disabilities - users who benefit from clear language, consistent layouts, and predictable navigation
- +Temporary impairments - anyone with a broken arm, a bright screen in sunlight, or slow internet
The four WCAG principles (POUR)
Perceivable
Information and UI components must be presentable to users in ways they can perceive. Content cannot be invisible to all of a user's senses.
Operable
UI components and navigation must be operable. Users must be able to operate the interface using a keyboard alone, without a mouse.
Understandable
Content and operation must be understandable. Text must be readable, and pages must behave in predictable ways.
Robust
Content must be robust enough to be interpreted reliably by a wide variety of assistive technologies, both current and future.
Implementation
How Accessibility Is Built Into Websites
Accessibility is not an afterthought or a bolt-on. It is built into the code, content, and design of a website from the start. These are the core technical practices.
Semantic HTML
Using the correct HTML elements for their intended purpose: headings, lists, buttons, and landmarks. Semantic markup gives screen readers the structure they need to navigate and announce content accurately.
Keyboard Navigation
Every interactive element, menus, forms, modals, carousels, must be fully operable using only a keyboard. Focus states must be clearly visible so users always know where they are on the page.
Colour Contrast
Text and UI elements must meet minimum contrast ratios against their backgrounds. WCAG 2.2 requires a ratio of at least 4.5:1 for normal text and 3:1 for large text and UI components.
Alternative Text for Images
Every meaningful image requires descriptive alt text so screen reader users understand what the image conveys. Decorative images are given an empty alt attribute so they are skipped.
Accessible Forms
All form inputs must have associated labels, error messages must be clearly communicated, and validation must not rely on colour alone. Forms are one of the most common sources of accessibility failures.
ARIA Roles and Attributes
Where native HTML falls short, ARIA (Accessible Rich Internet Applications) attributes add the semantic information assistive technologies need, particularly for complex interactive components like tabs, accordions, and dialogs.
Captions and Transcripts
All video content must include accurate captions for users who are deaf or hard of hearing. Audio-only content requires a text transcript. Auto-generated captions are not sufficient on their own.
Responsive and Zoomable Layouts
Sites must remain fully functional when text is resized up to 200% or when zoomed to 400% of the normal viewport. Content must not overflow or become obscured at larger text sizes.
Testing
How Accessibility Is Tested
Accessibility testing combines automated tools with manual review and real user testing. Automated tools find around 30-40% of issues, so manual checks are essential.
Tools like Axe, Lighthouse, and WAVE scan pages automatically and flag common issues including missing alt text, poor contrast, missing form labels, and invalid ARIA. A great first pass but not a complete audit.
Navigating the entire site using only the Tab, Shift+Tab, Enter, and arrow keys. Every action a mouse user can perform must be reachable and operable via keyboard, with no focus traps.
Testing with real screen readers: NVDA or JAWS on Windows, VoiceOver on Mac and iOS, and TalkBack on Android. Automated tools cannot fully replicate how a screen reader announces content to a user.
Manual checks using tools like the WebAIM Contrast Checker or browser DevTools to verify all text, icons, and focus indicators meet the required contrast ratios across all states including hover and focus.
Testing the site at 200% and 400% browser zoom to confirm layouts do not break, text does not overflow containers, and all functionality remains available without horizontal scrolling.
The gold standard. Real users with disabilities testing real tasks on your site. This uncovers usability barriers that technical testing alone will not find, and is increasingly expected by regulators for high-risk services.
UK and EU Accessibility Law
Web accessibility is not optional for many organisations. Both the UK and the EU have legal frameworks that require websites to meet accessibility standards, with enforcement mechanisms and potential penalties for non-compliance.
United Kingdom
Public Sector Bodies Accessibility Regulations 2018
All UK public sector websites and mobile apps must meet WCAG 2.1 Level AA. This covers central government, local councils, NHS, universities, and most publicly funded bodies. Sites must publish an accessibility statement and respond to accessibility feedback requests within 12 weeks.
Equality Act 2010
Private sector and charitable organisations in the UK are covered by the Equality Act 2010. Providing a website or digital service that is inaccessible to disabled people can constitute discrimination. Organisations have a legal duty to make "reasonable adjustments" to remove barriers for disabled users.
Who Enforces It?
The Central Digital and Data Office (CDDO) monitors public sector compliance. Equality Act claims can be brought by individuals through employment tribunals or civil courts. The Equality and Human Rights Commission (EHRC) can also take enforcement action.
Required standard: WCAG 2.1 Level AA
European Union
Web Accessibility Directive (WAD) 2016
The EU Web Accessibility Directive has applied to EU public sector websites since 2018. Like the UK regulation, it requires WCAG 2.1 Level AA compliance, an accessibility statement, and a feedback mechanism. Member states were required to establish monitoring and enforcement bodies.
European Accessibility Act (EAA) 2025
The most significant development in EU accessibility law. From 28 June 2025, the EAA extends mandatory accessibility requirements to the private sector across the EU. E-commerce websites, banking services, transport booking sites, streaming platforms, and digital communications services must all meet EN 301 549, the European standard that references WCAG 2.1 AA.
Who Is Affected by the EAA?
Any business that sells products or provides digital services to EU consumers, including UK businesses trading with EU customers. Microenterprises (fewer than 10 employees and annual turnover below EUR 2 million) are exempt from the EAA, but not from national non-discrimination law.
EAA deadline: 28 June 2025 - already in force
WCAG Conformance Levels Explained
Level A
The minimum. Addresses the most critical barriers. Failing Level A means some users simply cannot access your content at all.
Level AA
The legal requirement in the UK and EU. Addresses the most common and significant barriers. This is the target for all compliant websites.
Level AAA
The highest level. Not legally required for entire sites, but individual AAA criteria can be applied to improve the experience for specific user groups.
Make your website accessible and legally compliant
We can audit your existing site, fix accessibility issues, and ensure you meet WCAG 2.1 AA - the standard required by UK and EU law.