WCAG guidelines state that links should only open a new tab “when necessary”.

Why opening a new tab is bad for accessibility

  • New tabs are unexpected, unpredictable, non-default browser behavior.
  • New tabs break back-button history navigation.
  • New tabs are disorienting for some visually impaired users.
  • New tabs take away user control. Users can opt-in to a new tab with keyboard or mouse controls, but cannot opt-out.

Acceptable reasons to open a new tab

  • Yes: Navigating away will disrupt a multi-step workflow. For example, context sensitive help links on a form.
  • Yes: Navigating away will break a secure login session. For example, a banking transaction session.

Unacceptable reasons to open a new tab

  • No: A link is “external”, and leads to another website or domain.
  • No: The website maintainer wants to avoid losing user traffic to other sites.
  • No: A new tab will be convenient for the user (other than the two acceptable reasons mentioned above).

Reference

WCAG 2.0: G200: Opening new windows and tabs from a link only when necessary