Standard accessibility scans cannot reach pages behind a login screen. A scan sends automated requests to URLs, and any page requiring authentication returns a login prompt instead of the actual content. To evaluate protected pages, the scan needs an active, authenticated session.
| Key Point | What It Means |
|---|---|
| Why login pages block scans | Scans request pages via URL, and protected pages redirect to a login screen instead of serving the actual content. |
| Browser extension method | A browser extension runs within your active session, giving the scan access to any page you can see while logged in. |
| Coverage limitation | Scans, whether authenticated or not, only flag approximately 25% of accessibility issues. The remaining 75% requires human evaluation. |
Why Standard Scans Cannot Reach Protected Content
Most web applications place their core functionality behind authentication. Dashboards, account settings, user profiles, and transactional workflows all require a logged-in session.
When a scan requests one of these URLs without credentials, the server redirects to a login page. The scan then evaluates the login page itself, not the content that matters. Every protected page returns the same result: the login form.
How Browser Extensions Enable Accessibility Scan Authentication
The most common method for scanning authenticated pages uses a browser extension. You log into the application normally, and the extension runs its checks within your active browser session. Because the extension operates inside an already-authenticated context, it sees exactly what you see.
This approach works well for web applications, SaaS products, and internal tools. The extension evaluates the HTML, CSS, and ARIA attributes on the rendered page, applying the same automated checks it would apply to any public page.
What Authenticated Scans Can and Cannot Evaluate
Authenticated scans expand the scope of automated checks to include protected content. Form fields, interactive components, dynamic content areas, and role-specific views all become available for evaluation.
The limitation remains the same as with any scan: automated checks flag approximately 25% of accessibility issues. Screen reader behavior, logical reading order, keyboard interaction patterns, and context-dependent labeling all require a manual audit by an accessibility professional. Authentication does not change this ratio.
Scheduling and Monitoring for Authenticated Pages
Recurring scans (monitoring) present a distinct consideration for protected pages. Scheduled scans that run automatically may not be able to maintain an authenticated session without additional configuration. Session tokens expire, passwords change, and multi-factor authentication adds another layer of complexity.
Some scanning approaches address this through stored session credentials or API-based authentication tokens. The specifics vary by tool category. Browser-based extensions typically require a user to be actively logged in, which limits their use for fully automated monitoring schedules.
When Authentication Scanning Matters Most
Organizations with SaaS products or member portals have the strongest need for authenticated scanning. If the majority of a product’s functionality sits behind a login, scanning only the public-facing pages misses the application’s core experience.
Procurement processes increasingly ask for evidence of accessibility evaluation across an entire product, not only its marketing pages. Authenticated scans provide one piece of that evidence, alongside a complete audit that covers the remaining 75% of potential issues.