• Success Criterion 2.1.2
  • Conformance level A
  • W3C reference F10

Keyboard Focus Stuck Inside an Embedded Plugin or Widget

2.1.2 — No Keyboard Trap

Scenario

Setting

An email client's compose window

What’s wrong

Keyboard focus can get stuck inside an embedded plugin/format (video player, widget) and the user cannot Tab back out to the rest of the page.

Example

Here's what happens on an email client's compose window: keyboard focus can get stuck inside an embedded plugin/format (video player, widget) and the user cannot Tab back out to the rest of the page.

Why it matters

All keyboard and screen-reader users who can become stuck inside a component. Here, on an email client's compose window, the result is they get stuck and can't reach the control.

How to test

Tab into any embedded plugin/format (PDF viewer, old Flash-style widget): confirm Tab or Shift+Tab can move focus back out to the surrounding page.

How to fix

Ensure focus can Tab out of every embedded format/plugin back to the page.

Outcome

After the fix, the same visitor to an email client's compose window can now reach and operate the control without a mouse.

Who is affected

All keyboard and screen-reader users who can become stuck inside a component.

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