a11y-analyzer

Accessibility Analyzer

Analyze accessibility from real user sessions — keyboard navigation patterns, focus traps, missing labels, and a11y regressions. Complement automated audits with evidence from actual users.

When to Use

• "Are keyboard-only users able to navigate our checkout?"
• "Did the redesign break accessibility for screen reader users?"
• "Find sessions where users tabbed through the page — did they get stuck?"
• "Are our form labels working for assistive technology?"
• "Validate WCAG compliance from real session data"
• "Show me sessions where users struggled with focus order"

Mental Model

Automated a11y tools (Axe, Lighthouse) catch ~30% of accessibility issues. Real user sessions catch the rest — focus traps, keyboard dead ends, unlabeled interactive elements, content that changes without announcement.

Fullstory captures all DOM interactions. By looking at how users interact with your site without a mouse, you can identify where the experience breaks.

Workflow

Step 1: Identify a11y-relevant sessions

Build segments for users likely relying on assistive technology:

fullstory:build_segment("users who navigated using only keyboard (tab key usage, no mouse clicks)")
fullstory:build_segment("users who used form fields extensively (screen reader users fill forms via keyboard)")

Or filter sessions by interaction patterns:

fullstory:get_sessions(
  event="keydown",      # keyboard interactions
  exclude_event="click", # no mouse clicks = likely keyboard-only
  limit=10
)

Step 2: Audit keyboard navigation

For each keyboard-navigated session, use session-context agent: "What was the user's tab order? Did they tab through elements in a logical sequence? Did they get trapped in any element (modal, form, menu)? Were there dead tab stops where nothing was focused?"

Common keyboard issues:

• Focus trap: User tabs into a modal/dropdown and can't tab out
• Skip link missing: User tabs through 50 nav items before reaching content
• Focus not visible: Element receives focus but no focus ring — user doesn't know where they are
• Tab order illogical: Focus jumps from header to footer, skipping main content