A website accessibility audit is a structured check of whether your site can be used by people with disabilities, measured against a recognised standard. In Europe that standard is EN 301 549, the EU's harmonised accessibility standard, which incorporates WCAG 2.1 AA. The audit produces a list of specific failures, each one ranked by severity, with a clear note on what to fix.
Here is the reassuring part. You do not need a £15,000 consultancy to start. You also will not get there with a one-click scanner on its own, because automated tools catch only part of what the standard requires. The honest answer sits in the middle: a method you can run yourself, this week, that mixes a machine scan with a few manual checks anyone on your team can learn.
This guide is that method. It covers what an audit actually checks, the six steps to run one, how to choose between an automated scan, a consultancy and a guided platform, and how to turn a one-off audit into ongoing compliance.
What a Website Accessibility Audit Actually Checks
Every audit measures your site against a standard. In the EU that standard is EN 301 549, the bloc's harmonised accessibility standard, and it incorporates WCAG 2.1 AA(opens in new tab). WCAG, the Web Content Accessibility Guidelines, is the part most people have heard of, so it helps to name both: WCAG is the technical checklist, and EN 301 549 is the legal wrapper that European accessibility law points to.
WCAG is organised around four principles, and they make a useful spine for any audit:
- Perceivable. Can people take in the content, whether they see it, hear it, or read it through assistive technology (software that helps people with disabilities use a device)?
- Operable. Can people use every control, including with a keyboard alone?
- Understandable. Is the content readable, and does the interface behave the way people expect?
- Robust. Does the underlying code work reliably with screen readers and other tools?
A useful way to hold the four principles in mind is to ask what a real person is trying to do. Someone using a screen reader is trying to perceive your content. Someone with a hand tremor or no mouse is trying to operate it. Someone with a cognitive difference is trying to understand it. And robust is the quiet one underneath, the assurance that the markup behaves with whatever tool the person brings. An audit grades those tasks, not just the lines of code that sit behind them.
Here is the point that shapes the whole method. Independent industry research consistently puts the share of WCAG issues an automated tool can detect at roughly 30 to 40 percent. The rest need a person. A scanner cannot tell you whether a keyboard trap leaves someone stuck, whether alt text is meaningful, whether focus order is logical, or whether a label actually describes its field. That is exactly why a real audit has two passes: an automated one to clear the machine-detectable failures fast, and a manual one to catch everything that needs judgement.
If you want the wider concept first, start with our guide to accessibility testing. For what a regulator-grade audit tests in detail, see what an EAA audit checks.
How to Run a Website Accessibility Audit: 6 Steps
You can run the first version of this in a week, and you already have most of the tools. You need a browser, a keyboard, a screen reader that is free or already installed, and a single document to record what you find. Work through the steps in order, because each one builds on the last.
- Define your scope. Do not try to audit every page. Pick the journeys that matter most: your homepage, sign-up, checkout and account pages, plus your highest-traffic content. Most failures repeat across templates, so a representative sample finds the bulk of the problems without forcing you to check all thousand pages. Write the list down before you start, so the audit has clear edges.
- Run an automated scan first. A free browser tool, such as our AUDITSU Web Scanner extension, catches the obvious, machine-detectable failures: missing alt attributes, low colour contrast, missing form labels and a missing page language setting. Fix what it finds, then move on. This is the floor of your audit, not the whole building.
- Test with a keyboard. Put the mouse aside. Using only Tab, Shift and Tab, Enter, Space and the arrow keys, can you reach and operate every control? Is the focus indicator (the visible outline showing where you are) always there? Can you open and close every menu and modal, and escape each one without getting trapped? This single pass surfaces failures that no scanner will ever report.
- Test with a screen reader. Use VoiceOver, which is built into macOS and iOS, or NVDA(opens in new tab), a free screen reader for Windows. Do images, buttons and links announce something meaningful? Is the heading structure logical as you move through it? Do form errors get read out when they appear? Listening to your own site for ten minutes is one of the most revealing tests you can run.
- Check the human-judgement items. These are the things only a person can grade. Is the alt text meaningful, rather than something like "image123.jpg"? Does link text make sense when read on its own? Does any information rely on colour alone? Is the language plain enough to follow? Do videos have captions?
- Record every finding as evidence. For each failure, note four things: the page, the WCAG criterion it breaks, the severity, and the fix. That list is your audit. It is also the evidence trail you will want if a regulator or a customer ever asks how you meet the standard.
The audit is not the scan. The scan is step two of six. The other five are where most real failures live, and they are the ones that lead to a complaint.
A first pass over a handful of key pages is usually a day or two of focused work, not a quarter-long project. The aim of that first pass is not perfection. It is an honest, written picture of where you stand, so the next decision, what to fix and in what order, is based on evidence rather than a guess.
Automated Scan, Consultancy Audit, or Guided Platform?
Once you know the method, the real decision is which tool does which part. There are three honest options, and the right one depends on where you are today.
Free automated scanners
Our own AUDITSU Web Scanner is a free Chrome extension that runs WCAG and EN 301 549 checks on any page you visit, right in the browser, so you can clear the machine-detectable failures without leaving the site you are testing. Other well-known free tools, such as axe DevTools, WAVE and Lighthouse, do the same job in slightly different ways. All of them are excellent, free and instant, and you should run one on every release. Their shared ceiling is the figure above: no scanner can tell you whether alt text is meaningful, or whether a flow is genuinely operable. Use one as step two of the method. It is a strong floor and a poor whole.
Consultancy manual audit
A specialist agency will do the manual passes for you, thoroughly and with real expertise. The cost runs from roughly £15,000 to £50,000 depending on scope, and you pay it again each time the product changes in a meaningful way. The deeper problem is staleness: a point-in-time PDF starts going out of date the next sprint, so the document you paid for no longer matches the site you actually ship.
Guided in-house platform
The middle path structures the manual passes, the keyboard test, the screen reader test and the judgement items, so that someone who is not an accessibility specialist can run them properly. It keeps the findings as a living, re-runnable record rather than a one-off report. This is the gap the rest of the market leaves open: most products give you either a shallow instant scan or an expensive human audit, and nothing that lets a normal team run the full method itself.
None of these is wrong. If your site is small and simple, a free scanner plus a careful manual pass may be all you need this quarter. If you are in a regulated sector, or your site is large and changes often, you will want either the expert depth of a consultancy or the repeatable structure of a platform, because a one-off check cannot keep pace with what you ship. The point is to choose with your eyes open, not to assume a single scan has done the job.
Turning a Website Audit Into Ongoing Compliance
An audit is a snapshot, and accessibility regresses every time you ship. A new component, a redesigned form, a third-party embed: any of these can reintroduce a failure you had already fixed. So the asset you actually want is a repeatable audit, not a single report that ages on a shelf.
Once you have findings, two outputs follow. The first is a remediation backlog, ranked by severity, that your team works through like any other set of tickets. The second is a public accessibility statement, which declares your current conformance status and gives users a clear way to report problems they run into.
In practice, that means running the audit on a rhythm rather than once. A light re-check on every significant release, and a fuller pass on a set schedule, keeps the picture honest as the site moves. The keyboard and screen reader passes from step three and four are quick once the team has done them a few times, so the cost of staying current is far lower than the cost of a yearly rescue project.
There is a regulatory reason to keep this current. The European Accessibility Act has applied since 28 June 2025, and it requires many digital services in the EU to meet EN 301 549. A maintained audit record is how you show that you do. No company has been fined under the Act as of June 2026, so there is no cause for alarm. Treat a current audit as an early-mover advantage, not a fire drill.
Audit your website for free
AUDITSU lets product and compliance teams audit their website for free. It guides you through the structured manual passes, the keyboard test, the screen reader test and the human-judgement items, step by step, and keeps your findings as a living, re-runnable record against EN 301 549 and WCAG 2.1 AA. You do not need accessibility expertise, and there is no consultancy fee. Mobile apps are covered too, on the Beta plan.
If you have read this far, the fastest next step is to run the method on your own site. Start a free website audit below, or explore the full platform on our homepage.