Automated scan vs. manual audit — what's the real difference?
In short: An automated scan checks your code against machine-testable WCAG rules in seconds — ideal for a first pass and ongoing monitoring — but industry estimates put automated coverage at roughly 30–40% of WCAG issues. A manual audit adds what code can't show: contrast in context, keyboard use and screen-reader behaviour. You need both, not one or the other.
Both are legitimate parts of an accessibility program, but they catch different things. Here's an honest breakdown of what each one covers, so you know when a scan is enough and when you need a human.
| Automated scan | Manual audit | |
|---|---|---|
| Speed | Seconds — results while you wait. | Days to weeks, depending on site size. |
| Cost | Free to a few hundred euros/month for continuous monitoring. | Typically €1,000–5,000+ per audit, more for large sites. |
| Missing alt text, unlabeled form fields, missing document title/lang | Detected reliably — this is exactly what code-level analysis is built for. | Also caught, but slower and more expensive for the same finding. |
| Color contrast | Partial — inline-style contrast can be computed; CSS-class-based colors generally can't, without rendering the page. | Fully covered — a real browser renders the computed styles. |
| Keyboard navigation & focus traps | Not covered — requires actually tabbing through the interface. | Fully covered — testers navigate with a keyboard only. |
| Screen reader experience | Not covered — a scanner doesn't listen to what gets announced. | Fully covered — testers use NVDA/JAWS/VoiceOver directly. |
| Dynamic content & JS-rendered UI | Limited — static analysis sees the initial HTML, not everything JavaScript adds afterward. | Fully covered — testers interact with the live, rendered app. |
| Consistency & regression tracking | Excellent — same rules, run automatically every time your site changes. | Depends on how often you re-commission an audit. |
| Legal/expert judgment calls | None — a scanner flags patterns, it doesn't interpret intent or context. | Included — auditors weigh context and produce a signed report. |
Our honest recommendation
Use an automated scan as your first pass and for ongoing regression monitoring — it's fast, free or cheap, and catches a meaningful share of common WCAG issues at the code level. Before publishing a compliance or accessibility statement, or if your business is squarely in scope of the EAA/BFSG/Legge Stanca, commission a manual audit for what code can't see: contrast, keyboard, and screen-reader behavior. The two are complementary, not competing.
Run a free automated scan →